/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_descrip.c 8.6 (Berkeley) 4/19/94 */ #include #include "opt_capsicum.h" #include "opt_ddb.h" #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static MALLOC_DEFINE(M_FILEDESC, "filedesc", "Open file descriptor table"); static MALLOC_DEFINE(M_PWD, "pwd", "Descriptor table vnodes"); static MALLOC_DEFINE(M_PWDDESC, "pwddesc", "Pwd descriptors"); static MALLOC_DEFINE(M_FILEDESC_TO_LEADER, "filedesc_to_leader", "file desc to leader structures"); static MALLOC_DEFINE(M_SIGIO, "sigio", "sigio structures"); MALLOC_DEFINE(M_FILECAPS, "filecaps", "descriptor capabilities"); MALLOC_DECLARE(M_FADVISE); static __read_mostly uma_zone_t file_zone; static __read_mostly uma_zone_t filedesc0_zone; __read_mostly uma_zone_t pwd_zone; VFS_SMR_DECLARE; static int closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool holdleaders, bool audit); static void export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, struct kinfo_file *kif, struct filedesc *fdp, int flags); static int fd_first_free(struct filedesc *fdp, int low, int size); static void fdgrowtable(struct filedesc *fdp, int nfd); static void fdgrowtable_exp(struct filedesc *fdp, int nfd); static void fdunused(struct filedesc *fdp, int fd); static void fdused(struct filedesc *fdp, int fd); static int fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp); static int getmaxfd(struct thread *td); static u_long *filecaps_copy_prep(const struct filecaps *src); static void filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, u_long *ioctls); static u_long *filecaps_free_prep(struct filecaps *fcaps); static void filecaps_free_finish(u_long *ioctls); static struct pwd *pwd_alloc(void); /* * Each process has: * * - An array of open file descriptors (fd_ofiles) * - An array of file flags (fd_ofileflags) * - A bitmap recording which descriptors are in use (fd_map) * * A process starts out with NDFILE descriptors. The value of NDFILE has * been selected based the historical limit of 20 open files, and an * assumption that the majority of processes, especially short-lived * processes like shells, will never need more. * * If this initial allocation is exhausted, a larger descriptor table and * map are allocated dynamically, and the pointers in the process's struct * filedesc are updated to point to those. This is repeated every time * the process runs out of file descriptors (provided it hasn't hit its * resource limit). * * Since threads may hold references to individual descriptor table * entries, the tables are never freed. Instead, they are placed on a * linked list and freed only when the struct filedesc is released. */ #define NDFILE 20 #define NDSLOTSIZE sizeof(NDSLOTTYPE) #define NDENTRIES (NDSLOTSIZE * __CHAR_BIT) #define NDSLOT(x) ((x) / NDENTRIES) #define NDBIT(x) ((NDSLOTTYPE)1 << ((x) % NDENTRIES)) #define NDSLOTS(x) (((x) + NDENTRIES - 1) / NDENTRIES) #define FILEDESC_FOREACH_FDE(fdp, _iterator, _fde) \ struct filedesc *_fdp = (fdp); \ int _lastfile = fdlastfile_single(_fdp); \ for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ if ((_fde = &_fdp->fd_ofiles[_iterator])->fde_file != NULL) #define FILEDESC_FOREACH_FP(fdp, _iterator, _fp) \ struct filedesc *_fdp = (fdp); \ int _lastfile = fdlastfile_single(_fdp); \ for (_iterator = 0; _iterator <= _lastfile; _iterator++) \ if ((_fp = _fdp->fd_ofiles[_iterator].fde_file) != NULL) /* * SLIST entry used to keep track of ofiles which must be reclaimed when * the process exits. */ struct freetable { struct fdescenttbl *ft_table; SLIST_ENTRY(freetable) ft_next; }; /* * Initial allocation: a filedesc structure + the head of SLIST used to * keep track of old ofiles + enough space for NDFILE descriptors. */ struct fdescenttbl0 { int fdt_nfiles; struct filedescent fdt_ofiles[NDFILE]; }; struct filedesc0 { struct filedesc fd_fd; SLIST_HEAD(, freetable) fd_free; struct fdescenttbl0 fd_dfiles; NDSLOTTYPE fd_dmap[NDSLOTS(NDFILE)]; }; /* * Descriptor management. */ static int __exclusive_cache_line openfiles; /* actual number of open files */ struct mtx sigio_lock; /* mtx to protect pointers to sigio */ void __read_mostly (*mq_fdclose)(struct thread *td, int fd, struct file *fp); /* * If low >= size, just return low. Otherwise find the first zero bit in the * given bitmap, starting at low and not exceeding size - 1. Return size if * not found. */ static int fd_first_free(struct filedesc *fdp, int low, int size) { NDSLOTTYPE *map = fdp->fd_map; NDSLOTTYPE mask; int off, maxoff; if (low >= size) return (low); off = NDSLOT(low); if (low % NDENTRIES) { mask = ~(~(NDSLOTTYPE)0 >> (NDENTRIES - (low % NDENTRIES))); if ((mask &= ~map[off]) != 0UL) return (off * NDENTRIES + ffsl(mask) - 1); ++off; } for (maxoff = NDSLOTS(size); off < maxoff; ++off) if (map[off] != ~0UL) return (off * NDENTRIES + ffsl(~map[off]) - 1); return (size); } /* * Find the last used fd. * * Call this variant if fdp can't be modified by anyone else (e.g, during exec). * Otherwise use fdlastfile. */ int fdlastfile_single(struct filedesc *fdp) { NDSLOTTYPE *map = fdp->fd_map; int off, minoff; off = NDSLOT(fdp->fd_nfiles - 1); for (minoff = NDSLOT(0); off >= minoff; --off) if (map[off] != 0) return (off * NDENTRIES + flsl(map[off]) - 1); return (-1); } int fdlastfile(struct filedesc *fdp) { FILEDESC_LOCK_ASSERT(fdp); return (fdlastfile_single(fdp)); } static int fdisused(struct filedesc *fdp, int fd) { KASSERT(fd >= 0 && fd < fdp->fd_nfiles, ("file descriptor %d out of range (0, %d)", fd, fdp->fd_nfiles)); return ((fdp->fd_map[NDSLOT(fd)] & NDBIT(fd)) != 0); } /* * Mark a file descriptor as used. */ static void fdused_init(struct filedesc *fdp, int fd) { KASSERT(!fdisused(fdp, fd), ("fd=%d is already used", fd)); fdp->fd_map[NDSLOT(fd)] |= NDBIT(fd); } static void fdused(struct filedesc *fdp, int fd) { FILEDESC_XLOCK_ASSERT(fdp); fdused_init(fdp, fd); if (fd == fdp->fd_freefile) fdp->fd_freefile++; } /* * Mark a file descriptor as unused. */ static void fdunused(struct filedesc *fdp, int fd) { FILEDESC_XLOCK_ASSERT(fdp); KASSERT(fdisused(fdp, fd), ("fd=%d is already unused", fd)); KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, ("fd=%d is still in use", fd)); fdp->fd_map[NDSLOT(fd)] &= ~NDBIT(fd); if (fd < fdp->fd_freefile) fdp->fd_freefile = fd; } /* * Free a file descriptor. * * Avoid some work if fdp is about to be destroyed. */ static inline void fdefree_last(struct filedescent *fde) { filecaps_free(&fde->fde_caps); } static inline void fdfree(struct filedesc *fdp, int fd) { struct filedescent *fde; FILEDESC_XLOCK_ASSERT(fdp); fde = &fdp->fd_ofiles[fd]; #ifdef CAPABILITIES seqc_write_begin(&fde->fde_seqc); #endif fde->fde_file = NULL; #ifdef CAPABILITIES seqc_write_end(&fde->fde_seqc); #endif fdefree_last(fde); fdunused(fdp, fd); } /* * System calls on descriptors. */ #ifndef _SYS_SYSPROTO_H_ struct getdtablesize_args { int dummy; }; #endif /* ARGSUSED */ int sys_getdtablesize(struct thread *td, struct getdtablesize_args *uap) { #ifdef RACCT uint64_t lim; #endif td->td_retval[0] = getmaxfd(td); #ifdef RACCT PROC_LOCK(td->td_proc); lim = racct_get_limit(td->td_proc, RACCT_NOFILE); PROC_UNLOCK(td->td_proc); if (lim < td->td_retval[0]) td->td_retval[0] = lim; #endif return (0); } /* * Duplicate a file descriptor to a particular value. * * Note: keep in mind that a potential race condition exists when closing * descriptors from a shared descriptor table (via rfork). */ #ifndef _SYS_SYSPROTO_H_ struct dup2_args { u_int from; u_int to; }; #endif /* ARGSUSED */ int sys_dup2(struct thread *td, struct dup2_args *uap) { return (kern_dup(td, FDDUP_FIXED, 0, (int)uap->from, (int)uap->to)); } /* * Duplicate a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct dup_args { u_int fd; }; #endif /* ARGSUSED */ int sys_dup(struct thread *td, struct dup_args *uap) { return (kern_dup(td, FDDUP_NORMAL, 0, (int)uap->fd, 0)); } /* * The file control system call. */ #ifndef _SYS_SYSPROTO_H_ struct fcntl_args { int fd; int cmd; long arg; }; #endif /* ARGSUSED */ int sys_fcntl(struct thread *td, struct fcntl_args *uap) { return (kern_fcntl_freebsd(td, uap->fd, uap->cmd, uap->arg)); } int kern_fcntl_freebsd(struct thread *td, int fd, int cmd, long arg) { struct flock fl; struct __oflock ofl; intptr_t arg1; int error, newcmd; error = 0; newcmd = cmd; switch (cmd) { case F_OGETLK: case F_OSETLK: case F_OSETLKW: /* * Convert old flock structure to new. */ error = copyin((void *)(intptr_t)arg, &ofl, sizeof(ofl)); fl.l_start = ofl.l_start; fl.l_len = ofl.l_len; fl.l_pid = ofl.l_pid; fl.l_type = ofl.l_type; fl.l_whence = ofl.l_whence; fl.l_sysid = 0; switch (cmd) { case F_OGETLK: newcmd = F_GETLK; break; case F_OSETLK: newcmd = F_SETLK; break; case F_OSETLKW: newcmd = F_SETLKW; break; } arg1 = (intptr_t)&fl; break; case F_GETLK: case F_SETLK: case F_SETLKW: case F_SETLK_REMOTE: error = copyin((void *)(intptr_t)arg, &fl, sizeof(fl)); arg1 = (intptr_t)&fl; break; default: arg1 = arg; break; } if (error) return (error); error = kern_fcntl(td, fd, newcmd, arg1); if (error) return (error); if (cmd == F_OGETLK) { ofl.l_start = fl.l_start; ofl.l_len = fl.l_len; ofl.l_pid = fl.l_pid; ofl.l_type = fl.l_type; ofl.l_whence = fl.l_whence; error = copyout(&ofl, (void *)(intptr_t)arg, sizeof(ofl)); } else if (cmd == F_GETLK) { error = copyout(&fl, (void *)(intptr_t)arg, sizeof(fl)); } return (error); } int kern_fcntl(struct thread *td, int fd, int cmd, intptr_t arg) { struct filedesc *fdp; struct flock *flp; struct file *fp, *fp2; struct filedescent *fde; struct proc *p; struct vnode *vp; struct mount *mp; struct kinfo_file *kif; int error, flg, kif_sz, seals, tmp, got_set, got_cleared; uint64_t bsize; off_t foffset; error = 0; flg = F_POSIX; p = td->td_proc; fdp = p->p_fd; AUDIT_ARG_FD(cmd); AUDIT_ARG_CMD(cmd); switch (cmd) { case F_DUPFD: tmp = arg; error = kern_dup(td, FDDUP_FCNTL, 0, fd, tmp); break; case F_DUPFD_CLOEXEC: tmp = arg; error = kern_dup(td, FDDUP_FCNTL, FDDUP_FLAG_CLOEXEC, fd, tmp); break; case F_DUP2FD: tmp = arg; error = kern_dup(td, FDDUP_FIXED, 0, fd, tmp); break; case F_DUP2FD_CLOEXEC: tmp = arg; error = kern_dup(td, FDDUP_FIXED, FDDUP_FLAG_CLOEXEC, fd, tmp); break; case F_GETFD: error = EBADF; FILEDESC_SLOCK(fdp); fde = fdeget_noref(fdp, fd); if (fde != NULL) { td->td_retval[0] = (fde->fde_flags & UF_EXCLOSE) ? FD_CLOEXEC : 0; error = 0; } FILEDESC_SUNLOCK(fdp); break; case F_SETFD: error = EBADF; FILEDESC_XLOCK(fdp); fde = fdeget_noref(fdp, fd); if (fde != NULL) { fde->fde_flags = (fde->fde_flags & ~UF_EXCLOSE) | (arg & FD_CLOEXEC ? UF_EXCLOSE : 0); error = 0; } FILEDESC_XUNLOCK(fdp); break; case F_GETFL: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETFL, &fp); if (error != 0) break; td->td_retval[0] = OFLAGS(fp->f_flag); fdrop(fp, td); break; case F_SETFL: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETFL, &fp); if (error != 0) break; if (fp->f_ops == &path_fileops) { fdrop(fp, td); error = EBADF; break; } do { tmp = flg = fp->f_flag; tmp &= ~FCNTLFLAGS; tmp |= FFLAGS(arg & ~O_ACCMODE) & FCNTLFLAGS; } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); got_set = tmp & ~flg; got_cleared = flg & ~tmp; tmp = fp->f_flag & FNONBLOCK; error = fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); if (error != 0) goto revert_f_setfl; tmp = fp->f_flag & FASYNC; error = fo_ioctl(fp, FIOASYNC, &tmp, td->td_ucred, td); if (error == 0) { fdrop(fp, td); break; } atomic_clear_int(&fp->f_flag, FNONBLOCK); tmp = 0; (void)fo_ioctl(fp, FIONBIO, &tmp, td->td_ucred, td); revert_f_setfl: do { tmp = flg = fp->f_flag; tmp &= ~FCNTLFLAGS; tmp |= got_cleared; tmp &= ~got_set; } while (atomic_cmpset_int(&fp->f_flag, flg, tmp) == 0); fdrop(fp, td); break; case F_GETOWN: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_GETOWN, &fp); if (error != 0) break; error = fo_ioctl(fp, FIOGETOWN, &tmp, td->td_ucred, td); if (error == 0) td->td_retval[0] = tmp; fdrop(fp, td); break; case F_SETOWN: error = fget_fcntl(td, fd, &cap_fcntl_rights, F_SETOWN, &fp); if (error != 0) break; tmp = arg; error = fo_ioctl(fp, FIOSETOWN, &tmp, td->td_ucred, td); fdrop(fp, td); break; case F_SETLK_REMOTE: error = priv_check(td, PRIV_NFS_LOCKD); if (error != 0) return (error); flg = F_REMOTE; goto do_setlk; case F_SETLKW: flg |= F_WAIT; /* FALLTHROUGH F_SETLK */ case F_SETLK: do_setlk: flp = (struct flock *)arg; if ((flg & F_REMOTE) != 0 && flp->l_sysid == 0) { error = EINVAL; break; } error = fget_unlocked(td, fd, &cap_flock_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { error = EBADF; fdrop(fp, td); break; } if (flp->l_whence == SEEK_CUR) { foffset = foffset_get(fp); if (foffset < 0 || (flp->l_start > 0 && foffset > OFF_MAX - flp->l_start)) { error = EOVERFLOW; fdrop(fp, td); break; } flp->l_start += foffset; } vp = fp->f_vnode; switch (flp->l_type) { case F_RDLCK: if ((fp->f_flag & FREAD) == 0) { error = EBADF; break; } if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { PROC_LOCK(p->p_leader); p->p_leader->p_flag |= P_ADVLOCK; PROC_UNLOCK(p->p_leader); } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, flp, flg); break; case F_WRLCK: if ((fp->f_flag & FWRITE) == 0) { error = EBADF; break; } if ((p->p_leader->p_flag & P_ADVLOCK) == 0) { PROC_LOCK(p->p_leader); p->p_leader->p_flag |= P_ADVLOCK; PROC_UNLOCK(p->p_leader); } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_SETLK, flp, flg); break; case F_UNLCK: error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, flp, flg); break; case F_UNLCKSYS: if (flg != F_REMOTE) { error = EINVAL; break; } error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCKSYS, flp, flg); break; default: error = EINVAL; break; } if (error != 0 || flp->l_type == F_UNLCK || flp->l_type == F_UNLCKSYS) { fdrop(fp, td); break; } /* * Check for a race with close. * * The vnode is now advisory locked (or unlocked, but this case * is not really important) as the caller requested. * We had to drop the filedesc lock, so we need to recheck if * the descriptor is still valid, because if it was closed * in the meantime we need to remove advisory lock from the * vnode - close on any descriptor leading to an advisory * locked vnode, removes that lock. * We will return 0 on purpose in that case, as the result of * successful advisory lock might have been externally visible * already. This is fine - effectively we pretend to the caller * that the closing thread was a bit slower and that the * advisory lock succeeded before the close. */ error = fget_unlocked(td, fd, &cap_no_rights, &fp2); if (error != 0) { fdrop(fp, td); break; } if (fp != fp2) { flp->l_whence = SEEK_SET; flp->l_start = 0; flp->l_len = 0; flp->l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, flp, F_POSIX); } fdrop(fp, td); fdrop(fp2, td); break; case F_GETLK: error = fget_unlocked(td, fd, &cap_flock_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { error = EBADF; fdrop(fp, td); break; } flp = (struct flock *)arg; if (flp->l_type != F_RDLCK && flp->l_type != F_WRLCK && flp->l_type != F_UNLCK) { error = EINVAL; fdrop(fp, td); break; } if (flp->l_whence == SEEK_CUR) { foffset = foffset_get(fp); if ((flp->l_start > 0 && foffset > OFF_MAX - flp->l_start) || (flp->l_start < 0 && foffset < OFF_MIN - flp->l_start)) { error = EOVERFLOW; fdrop(fp, td); break; } flp->l_start += foffset; } vp = fp->f_vnode; error = VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_GETLK, flp, F_POSIX); fdrop(fp, td); break; case F_ADD_SEALS: error = fget_unlocked(td, fd, &cap_no_rights, &fp); if (error != 0) break; error = fo_add_seals(fp, arg); fdrop(fp, td); break; case F_GET_SEALS: error = fget_unlocked(td, fd, &cap_no_rights, &fp); if (error != 0) break; if (fo_get_seals(fp, &seals) == 0) td->td_retval[0] = seals; else error = EINVAL; fdrop(fp, td); break; case F_RDAHEAD: arg = arg ? 128 * 1024: 0; /* FALLTHROUGH */ case F_READAHEAD: error = fget_unlocked(td, fd, &cap_no_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE || fp->f_ops == &path_fileops) { fdrop(fp, td); error = EBADF; break; } vp = fp->f_vnode; if (vp->v_type != VREG) { fdrop(fp, td); error = ENOTTY; break; } /* * Exclusive lock synchronizes against f_seqcount reads and * writes in sequential_heuristic(). */ error = vn_lock(vp, LK_EXCLUSIVE); if (error != 0) { fdrop(fp, td); break; } if (arg >= 0) { bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; arg = MIN(arg, INT_MAX - bsize + 1); fp->f_seqcount[UIO_READ] = MIN(IO_SEQMAX, (arg + bsize - 1) / bsize); atomic_set_int(&fp->f_flag, FRDAHEAD); } else { atomic_clear_int(&fp->f_flag, FRDAHEAD); } VOP_UNLOCK(vp); fdrop(fp, td); break; case F_ISUNIONSTACK: /* * Check if the vnode is part of a union stack (either the * "union" flag from mount(2) or unionfs). * * Prior to introduction of this op libc's readdir would call * fstatfs(2), in effect unnecessarily copying kilobytes of * data just to check fs name and a mount flag. * * Fixing the code to handle everything in the kernel instead * is a non-trivial endeavor and has low priority, thus this * horrible kludge facilitates the current behavior in a much * cheaper manner until someone(tm) sorts this out. */ error = fget_unlocked(td, fd, &cap_no_rights, &fp); if (error != 0) break; if (fp->f_type != DTYPE_VNODE) { fdrop(fp, td); error = EBADF; break; } vp = fp->f_vnode; /* * Since we don't prevent dooming the vnode even non-null mp * found can become immediately stale. This is tolerable since * mount points are type-stable (providing safe memory access) * and any vfs op on this vnode going forward will return an * error (meaning return value in this case is meaningless). */ mp = atomic_load_ptr(&vp->v_mount); if (__predict_false(mp == NULL)) { fdrop(fp, td); error = EBADF; break; } td->td_retval[0] = 0; if (mp->mnt_kern_flag & MNTK_UNIONFS || mp->mnt_flag & MNT_UNION) td->td_retval[0] = 1; fdrop(fp, td); break; case F_KINFO: #ifdef CAPABILITY_MODE if (IN_CAPABILITY_MODE(td)) { error = ECAPMODE; break; } #endif error = copyin((void *)arg, &kif_sz, sizeof(kif_sz)); if (error != 0) break; if (kif_sz != sizeof(*kif)) { error = EINVAL; break; } kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK | M_ZERO); FILEDESC_SLOCK(fdp); error = fget_cap_noref(fdp, fd, &cap_fcntl_rights, &fp, NULL); if (error == 0 && fhold(fp)) { export_file_to_kinfo(fp, fd, NULL, kif, fdp, 0); FILEDESC_SUNLOCK(fdp); fdrop(fp, td); if ((kif->kf_status & KF_ATTR_VALID) != 0) { kif->kf_structsize = sizeof(*kif); error = copyout(kif, (void *)arg, sizeof(*kif)); } else { error = EBADF; } } else { FILEDESC_SUNLOCK(fdp); if (error == 0) error = EBADF; } free(kif, M_TEMP); break; default: error = EINVAL; break; } return (error); } static int getmaxfd(struct thread *td) { return (min((int)lim_cur(td, RLIMIT_NOFILE), maxfilesperproc)); } /* * Common code for dup, dup2, fcntl(F_DUPFD) and fcntl(F_DUP2FD). */ int kern_dup(struct thread *td, u_int mode, int flags, int old, int new) { struct filedesc *fdp; struct filedescent *oldfde, *newfde; struct proc *p; struct file *delfp, *oldfp; u_long *oioctls, *nioctls; int error, maxfd; p = td->td_proc; fdp = p->p_fd; oioctls = NULL; MPASS((flags & ~(FDDUP_FLAG_CLOEXEC)) == 0); MPASS(mode < FDDUP_LASTMODE); AUDIT_ARG_FD(old); /* XXXRW: if (flags & FDDUP_FIXED) AUDIT_ARG_FD2(new); */ /* * Verify we have a valid descriptor to dup from and possibly to * dup to. Unlike dup() and dup2(), fcntl()'s F_DUPFD should * return EINVAL when the new descriptor is out of bounds. */ if (old < 0) return (EBADF); if (new < 0) return (mode == FDDUP_FCNTL ? EINVAL : EBADF); maxfd = getmaxfd(td); if (new >= maxfd) return (mode == FDDUP_FCNTL ? EINVAL : EBADF); error = EBADF; FILEDESC_XLOCK(fdp); if (fget_noref(fdp, old) == NULL) goto unlock; if (mode == FDDUP_FIXED && old == new) { td->td_retval[0] = new; if (flags & FDDUP_FLAG_CLOEXEC) fdp->fd_ofiles[new].fde_flags |= UF_EXCLOSE; error = 0; goto unlock; } oldfde = &fdp->fd_ofiles[old]; oldfp = oldfde->fde_file; if (!fhold(oldfp)) goto unlock; /* * If the caller specified a file descriptor, make sure the file * table is large enough to hold it, and grab it. Otherwise, just * allocate a new descriptor the usual way. */ switch (mode) { case FDDUP_NORMAL: case FDDUP_FCNTL: if ((error = fdalloc(td, new, &new)) != 0) { fdrop(oldfp, td); goto unlock; } break; case FDDUP_FIXED: if (new >= fdp->fd_nfiles) { /* * The resource limits are here instead of e.g. * fdalloc(), because the file descriptor table may be * shared between processes, so we can't really use * racct_add()/racct_sub(). Instead of counting the * number of actually allocated descriptors, just put * the limit on the size of the file descriptor table. */ #ifdef RACCT if (RACCT_ENABLED()) { error = racct_set_unlocked(p, RACCT_NOFILE, new + 1); if (error != 0) { error = EMFILE; fdrop(oldfp, td); goto unlock; } } #endif fdgrowtable_exp(fdp, new + 1); } if (!fdisused(fdp, new)) fdused(fdp, new); break; default: KASSERT(0, ("%s unsupported mode %d", __func__, mode)); } KASSERT(old != new, ("new fd is same as old")); /* Refetch oldfde because the table may have grown and old one freed. */ oldfde = &fdp->fd_ofiles[old]; KASSERT(oldfp == oldfde->fde_file, ("fdt_ofiles shift from growth observed at fd %d", old)); newfde = &fdp->fd_ofiles[new]; delfp = newfde->fde_file; nioctls = filecaps_copy_prep(&oldfde->fde_caps); /* * Duplicate the source descriptor. */ #ifdef CAPABILITIES seqc_write_begin(&newfde->fde_seqc); #endif oioctls = filecaps_free_prep(&newfde->fde_caps); fde_copy(oldfde, newfde); filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, nioctls); if ((flags & FDDUP_FLAG_CLOEXEC) != 0) newfde->fde_flags = oldfde->fde_flags | UF_EXCLOSE; else newfde->fde_flags = oldfde->fde_flags & ~UF_EXCLOSE; #ifdef CAPABILITIES seqc_write_end(&newfde->fde_seqc); #endif td->td_retval[0] = new; error = 0; if (delfp != NULL) { (void) closefp(fdp, new, delfp, td, true, false); FILEDESC_UNLOCK_ASSERT(fdp); } else { unlock: FILEDESC_XUNLOCK(fdp); } filecaps_free_finish(oioctls); return (error); } static void sigiofree(struct sigio *sigio) { crfree(sigio->sio_ucred); free(sigio, M_SIGIO); } static struct sigio * funsetown_locked(struct sigio *sigio) { struct proc *p; struct pgrp *pg; SIGIO_ASSERT_LOCKED(); if (sigio == NULL) return (NULL); *sigio->sio_myref = NULL; if (sigio->sio_pgid < 0) { pg = sigio->sio_pgrp; PGRP_LOCK(pg); SLIST_REMOVE(&pg->pg_sigiolst, sigio, sigio, sio_pgsigio); PGRP_UNLOCK(pg); } else { p = sigio->sio_proc; PROC_LOCK(p); SLIST_REMOVE(&p->p_sigiolst, sigio, sigio, sio_pgsigio); PROC_UNLOCK(p); } return (sigio); } /* * If sigio is on the list associated with a process or process group, * disable signalling from the device, remove sigio from the list and * free sigio. */ void funsetown(struct sigio **sigiop) { struct sigio *sigio; /* Racy check, consumers must provide synchronization. */ if (*sigiop == NULL) return; SIGIO_LOCK(); sigio = funsetown_locked(*sigiop); SIGIO_UNLOCK(); if (sigio != NULL) sigiofree(sigio); } /* * Free a list of sigio structures. The caller must ensure that new sigio * structures cannot be added after this point. For process groups this is * guaranteed using the proctree lock; for processes, the P_WEXIT flag serves * as an interlock. */ void funsetownlst(struct sigiolst *sigiolst) { struct proc *p; struct pgrp *pg; struct sigio *sigio, *tmp; /* Racy check. */ sigio = SLIST_FIRST(sigiolst); if (sigio == NULL) return; p = NULL; pg = NULL; SIGIO_LOCK(); sigio = SLIST_FIRST(sigiolst); if (sigio == NULL) { SIGIO_UNLOCK(); return; } /* * Every entry of the list should belong to a single proc or pgrp. */ if (sigio->sio_pgid < 0) { pg = sigio->sio_pgrp; sx_assert(&proctree_lock, SX_XLOCKED); PGRP_LOCK(pg); } else /* if (sigio->sio_pgid > 0) */ { p = sigio->sio_proc; PROC_LOCK(p); KASSERT((p->p_flag & P_WEXIT) != 0, ("%s: process %p is not exiting", __func__, p)); } SLIST_FOREACH(sigio, sigiolst, sio_pgsigio) { *sigio->sio_myref = NULL; if (pg != NULL) { KASSERT(sigio->sio_pgid < 0, ("Proc sigio in pgrp sigio list")); KASSERT(sigio->sio_pgrp == pg, ("Bogus pgrp in sigio list")); } else /* if (p != NULL) */ { KASSERT(sigio->sio_pgid > 0, ("Pgrp sigio in proc sigio list")); KASSERT(sigio->sio_proc == p, ("Bogus proc in sigio list")); } } if (pg != NULL) PGRP_UNLOCK(pg); else PROC_UNLOCK(p); SIGIO_UNLOCK(); SLIST_FOREACH_SAFE(sigio, sigiolst, sio_pgsigio, tmp) sigiofree(sigio); } /* * This is common code for FIOSETOWN ioctl called by fcntl(fd, F_SETOWN, arg). * * After permission checking, add a sigio structure to the sigio list for * the process or process group. */ int fsetown(pid_t pgid, struct sigio **sigiop) { struct proc *proc; struct pgrp *pgrp; struct sigio *osigio, *sigio; int ret; if (pgid == 0) { funsetown(sigiop); return (0); } sigio = malloc(sizeof(struct sigio), M_SIGIO, M_WAITOK); sigio->sio_pgid = pgid; sigio->sio_ucred = crhold(curthread->td_ucred); sigio->sio_myref = sigiop; ret = 0; if (pgid > 0) { ret = pget(pgid, PGET_NOTWEXIT | PGET_NOTID | PGET_HOLD, &proc); SIGIO_LOCK(); osigio = funsetown_locked(*sigiop); if (ret == 0) { PROC_LOCK(proc); _PRELE(proc); if ((proc->p_flag & P_WEXIT) != 0) { ret = ESRCH; } else if (proc->p_session != curthread->td_proc->p_session) { /* * Policy - Don't allow a process to FSETOWN a * process in another session. * * Remove this test to allow maximum flexibility * or restrict FSETOWN to the current process or * process group for maximum safety. */ ret = EPERM; } else { sigio->sio_proc = proc; SLIST_INSERT_HEAD(&proc->p_sigiolst, sigio, sio_pgsigio); } PROC_UNLOCK(proc); } } else /* if (pgid < 0) */ { sx_slock(&proctree_lock); SIGIO_LOCK(); osigio = funsetown_locked(*sigiop); pgrp = pgfind(-pgid); if (pgrp == NULL) { ret = ESRCH; } else { if (pgrp->pg_session != curthread->td_proc->p_session) { /* * Policy - Don't allow a process to FSETOWN a * process in another session. * * Remove this test to allow maximum flexibility * or restrict FSETOWN to the current process or * process group for maximum safety. */ ret = EPERM; } else { sigio->sio_pgrp = pgrp; SLIST_INSERT_HEAD(&pgrp->pg_sigiolst, sigio, sio_pgsigio); } PGRP_UNLOCK(pgrp); } sx_sunlock(&proctree_lock); } if (ret == 0) *sigiop = sigio; SIGIO_UNLOCK(); if (osigio != NULL) sigiofree(osigio); return (ret); } /* * This is common code for FIOGETOWN ioctl called by fcntl(fd, F_GETOWN, arg). */ pid_t fgetown(struct sigio **sigiop) { pid_t pgid; SIGIO_LOCK(); pgid = (*sigiop != NULL) ? (*sigiop)->sio_pgid : 0; SIGIO_UNLOCK(); return (pgid); } static int closefp_impl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool audit) { int error; FILEDESC_XLOCK_ASSERT(fdp); /* * We now hold the fp reference that used to be owned by the * descriptor array. We have to unlock the FILEDESC *AFTER* * knote_fdclose to prevent a race of the fd getting opened, a knote * added, and deleteing a knote for the new fd. */ if (__predict_false(!TAILQ_EMPTY(&fdp->fd_kqlist))) knote_fdclose(td, fd); /* * We need to notify mqueue if the object is of type mqueue. */ if (__predict_false(fp->f_type == DTYPE_MQUEUE)) mq_fdclose(td, fd, fp); FILEDESC_XUNLOCK(fdp); #ifdef AUDIT if (AUDITING_TD(td) && audit) audit_sysclose(td, fd, fp); #endif error = closef(fp, td); /* * All paths leading up to closefp() will have already removed or * replaced the fd in the filedesc table, so a restart would not * operate on the same file. */ if (error == ERESTART) error = EINTR; return (error); } static int closefp_hl(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool holdleaders, bool audit) { int error; FILEDESC_XLOCK_ASSERT(fdp); if (holdleaders) { if (td->td_proc->p_fdtol != NULL) { /* * Ask fdfree() to sleep to ensure that all relevant * process leaders can be traversed in closef(). */ fdp->fd_holdleaderscount++; } else { holdleaders = false; } } error = closefp_impl(fdp, fd, fp, td, audit); if (holdleaders) { FILEDESC_XLOCK(fdp); fdp->fd_holdleaderscount--; if (fdp->fd_holdleaderscount == 0 && fdp->fd_holdleaderswakeup != 0) { fdp->fd_holdleaderswakeup = 0; wakeup(&fdp->fd_holdleaderscount); } FILEDESC_XUNLOCK(fdp); } return (error); } static int closefp(struct filedesc *fdp, int fd, struct file *fp, struct thread *td, bool holdleaders, bool audit) { FILEDESC_XLOCK_ASSERT(fdp); if (__predict_false(td->td_proc->p_fdtol != NULL)) { return (closefp_hl(fdp, fd, fp, td, holdleaders, audit)); } else { return (closefp_impl(fdp, fd, fp, td, audit)); } } /* * Close a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct close_args { int fd; }; #endif /* ARGSUSED */ int sys_close(struct thread *td, struct close_args *uap) { return (kern_close(td, uap->fd)); } int kern_close(struct thread *td, int fd) { struct filedesc *fdp; struct file *fp; fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); if ((fp = fget_noref(fdp, fd)) == NULL) { FILEDESC_XUNLOCK(fdp); return (EBADF); } fdfree(fdp, fd); /* closefp() drops the FILEDESC lock for us. */ return (closefp(fdp, fd, fp, td, true, true)); } static int close_range_cloexec(struct thread *td, u_int lowfd, u_int highfd) { struct filedesc *fdp; struct fdescenttbl *fdt; struct filedescent *fde; int fd; fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); fdt = atomic_load_ptr(&fdp->fd_files); highfd = MIN(highfd, fdt->fdt_nfiles - 1); fd = lowfd; if (__predict_false(fd > highfd)) { goto out_locked; } for (; fd <= highfd; fd++) { fde = &fdt->fdt_ofiles[fd]; if (fde->fde_file != NULL) fde->fde_flags |= UF_EXCLOSE; } out_locked: FILEDESC_XUNLOCK(fdp); return (0); } static int close_range_impl(struct thread *td, u_int lowfd, u_int highfd) { struct filedesc *fdp; const struct fdescenttbl *fdt; struct file *fp; int fd; fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); fdt = atomic_load_ptr(&fdp->fd_files); highfd = MIN(highfd, fdt->fdt_nfiles - 1); fd = lowfd; if (__predict_false(fd > highfd)) { goto out_locked; } for (;;) { fp = fdt->fdt_ofiles[fd].fde_file; if (fp == NULL) { if (fd == highfd) goto out_locked; } else { fdfree(fdp, fd); (void) closefp(fdp, fd, fp, td, true, true); if (fd == highfd) goto out_unlocked; FILEDESC_XLOCK(fdp); fdt = atomic_load_ptr(&fdp->fd_files); } fd++; } out_locked: FILEDESC_XUNLOCK(fdp); out_unlocked: return (0); } int kern_close_range(struct thread *td, int flags, u_int lowfd, u_int highfd) { /* * Check this prior to clamping; closefrom(3) with only fd 0, 1, and 2 * open should not be a usage error. From a close_range() perspective, * close_range(3, ~0U, 0) in the same scenario should also likely not * be a usage error as all fd above 3 are in-fact already closed. */ if (highfd < lowfd) { return (EINVAL); } if ((flags & CLOSE_RANGE_CLOEXEC) != 0) return (close_range_cloexec(td, lowfd, highfd)); return (close_range_impl(td, lowfd, highfd)); } #ifndef _SYS_SYSPROTO_H_ struct close_range_args { u_int lowfd; u_int highfd; int flags; }; #endif int sys_close_range(struct thread *td, struct close_range_args *uap) { AUDIT_ARG_FD(uap->lowfd); AUDIT_ARG_CMD(uap->highfd); AUDIT_ARG_FFLAGS(uap->flags); if ((uap->flags & ~(CLOSE_RANGE_CLOEXEC)) != 0) return (EINVAL); return (kern_close_range(td, uap->flags, uap->lowfd, uap->highfd)); } #ifdef COMPAT_FREEBSD12 /* * Close open file descriptors. */ #ifndef _SYS_SYSPROTO_H_ struct freebsd12_closefrom_args { int lowfd; }; #endif /* ARGSUSED */ int freebsd12_closefrom(struct thread *td, struct freebsd12_closefrom_args *uap) { u_int lowfd; AUDIT_ARG_FD(uap->lowfd); /* * Treat negative starting file descriptor values identical to * closefrom(0) which closes all files. */ lowfd = MAX(0, uap->lowfd); return (kern_close_range(td, 0, lowfd, ~0U)); } #endif /* COMPAT_FREEBSD12 */ #if defined(COMPAT_43) /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct ofstat_args { int fd; struct ostat *sb; }; #endif /* ARGSUSED */ int ofstat(struct thread *td, struct ofstat_args *uap) { struct ostat oub; struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) { cvtstat(&ub, &oub); error = copyout(&oub, uap->sb, sizeof(oub)); } return (error); } #endif /* COMPAT_43 */ #if defined(COMPAT_FREEBSD11) int freebsd11_fstat(struct thread *td, struct freebsd11_fstat_args *uap) { struct stat sb; struct freebsd11_stat osb; int error; error = kern_fstat(td, uap->fd, &sb); if (error != 0) return (error); error = freebsd11_cvtstat(&sb, &osb); if (error == 0) error = copyout(&osb, uap->sb, sizeof(osb)); return (error); } #endif /* COMPAT_FREEBSD11 */ /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct fstat_args { int fd; struct stat *sb; }; #endif /* ARGSUSED */ int sys_fstat(struct thread *td, struct fstat_args *uap) { struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error == 0) error = copyout(&ub, uap->sb, sizeof(ub)); return (error); } int kern_fstat(struct thread *td, int fd, struct stat *sbp) { struct file *fp; int error; AUDIT_ARG_FD(fd); error = fget(td, fd, &cap_fstat_rights, &fp); if (__predict_false(error != 0)) return (error); AUDIT_ARG_FILE(td->td_proc, fp); error = fo_stat(fp, sbp, td->td_ucred); fdrop(fp, td); #ifdef __STAT_TIME_T_EXT sbp->st_atim_ext = 0; sbp->st_mtim_ext = 0; sbp->st_ctim_ext = 0; sbp->st_btim_ext = 0; #endif #ifdef KTRACE if (KTRPOINT(td, KTR_STRUCT)) ktrstat_error(sbp, error); #endif return (error); } #if defined(COMPAT_FREEBSD11) /* * Return status information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct freebsd11_nfstat_args { int fd; struct nstat *sb; }; #endif /* ARGSUSED */ int freebsd11_nfstat(struct thread *td, struct freebsd11_nfstat_args *uap) { struct nstat nub; struct stat ub; int error; error = kern_fstat(td, uap->fd, &ub); if (error != 0) return (error); error = freebsd11_cvtnstat(&ub, &nub); if (error != 0) error = copyout(&nub, uap->sb, sizeof(nub)); return (error); } #endif /* COMPAT_FREEBSD11 */ /* * Return pathconf information about a file descriptor. */ #ifndef _SYS_SYSPROTO_H_ struct fpathconf_args { int fd; int name; }; #endif /* ARGSUSED */ int sys_fpathconf(struct thread *td, struct fpathconf_args *uap) { long value; int error; error = kern_fpathconf(td, uap->fd, uap->name, &value); if (error == 0) td->td_retval[0] = value; return (error); } int kern_fpathconf(struct thread *td, int fd, int name, long *valuep) { struct file *fp; struct vnode *vp; int error; error = fget(td, fd, &cap_fpathconf_rights, &fp); if (error != 0) return (error); if (name == _PC_ASYNC_IO) { *valuep = _POSIX_ASYNCHRONOUS_IO; goto out; } vp = fp->f_vnode; if (vp != NULL) { vn_lock(vp, LK_SHARED | LK_RETRY); error = VOP_PATHCONF(vp, name, valuep); VOP_UNLOCK(vp); } else if (fp->f_type == DTYPE_PIPE || fp->f_type == DTYPE_SOCKET) { if (name != _PC_PIPE_BUF) { error = EINVAL; } else { *valuep = PIPE_BUF; error = 0; } } else { error = EOPNOTSUPP; } out: fdrop(fp, td); return (error); } /* * Copy filecaps structure allocating memory for ioctls array if needed. * * The last parameter indicates whether the fdtable is locked. If it is not and * ioctls are encountered, copying fails and the caller must lock the table. * * Note that if the table was not locked, the caller has to check the relevant * sequence counter to determine whether the operation was successful. */ bool filecaps_copy(const struct filecaps *src, struct filecaps *dst, bool locked) { size_t size; if (src->fc_ioctls != NULL && !locked) return (false); memcpy(dst, src, sizeof(*src)); if (src->fc_ioctls == NULL) return (true); KASSERT(src->fc_nioctls > 0, ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; dst->fc_ioctls = malloc(size, M_FILECAPS, M_WAITOK); memcpy(dst->fc_ioctls, src->fc_ioctls, size); return (true); } static u_long * filecaps_copy_prep(const struct filecaps *src) { u_long *ioctls; size_t size; if (__predict_true(src->fc_ioctls == NULL)) return (NULL); KASSERT(src->fc_nioctls > 0, ("fc_ioctls != NULL, but fc_nioctls=%hd", src->fc_nioctls)); size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; ioctls = malloc(size, M_FILECAPS, M_WAITOK); return (ioctls); } static void filecaps_copy_finish(const struct filecaps *src, struct filecaps *dst, u_long *ioctls) { size_t size; *dst = *src; if (__predict_true(src->fc_ioctls == NULL)) { MPASS(ioctls == NULL); return; } size = sizeof(src->fc_ioctls[0]) * src->fc_nioctls; dst->fc_ioctls = ioctls; bcopy(src->fc_ioctls, dst->fc_ioctls, size); } /* * Move filecaps structure to the new place and clear the old place. */ void filecaps_move(struct filecaps *src, struct filecaps *dst) { *dst = *src; bzero(src, sizeof(*src)); } /* * Fill the given filecaps structure with full rights. */ static void filecaps_fill(struct filecaps *fcaps) { CAP_ALL(&fcaps->fc_rights); fcaps->fc_ioctls = NULL; fcaps->fc_nioctls = -1; fcaps->fc_fcntls = CAP_FCNTL_ALL; } /* * Free memory allocated within filecaps structure. */ static void filecaps_free_ioctl(struct filecaps *fcaps) { free(fcaps->fc_ioctls, M_FILECAPS); fcaps->fc_ioctls = NULL; } void filecaps_free(struct filecaps *fcaps) { filecaps_free_ioctl(fcaps); bzero(fcaps, sizeof(*fcaps)); } static u_long * filecaps_free_prep(struct filecaps *fcaps) { u_long *ioctls; ioctls = fcaps->fc_ioctls; bzero(fcaps, sizeof(*fcaps)); return (ioctls); } static void filecaps_free_finish(u_long *ioctls) { free(ioctls, M_FILECAPS); } /* * Validate the given filecaps structure. */ static void filecaps_validate(const struct filecaps *fcaps, const char *func) { KASSERT(cap_rights_is_valid(&fcaps->fc_rights), ("%s: invalid rights", func)); KASSERT((fcaps->fc_fcntls & ~CAP_FCNTL_ALL) == 0, ("%s: invalid fcntls", func)); KASSERT(fcaps->fc_fcntls == 0 || cap_rights_is_set(&fcaps->fc_rights, CAP_FCNTL), ("%s: fcntls without CAP_FCNTL", func)); /* * open calls without WANTIOCTLCAPS free caps but leave the counter */ #if 0 KASSERT(fcaps->fc_ioctls != NULL ? fcaps->fc_nioctls > 0 : (fcaps->fc_nioctls == -1 || fcaps->fc_nioctls == 0), ("%s: invalid ioctls", func)); #endif KASSERT(fcaps->fc_nioctls == 0 || cap_rights_is_set(&fcaps->fc_rights, CAP_IOCTL), ("%s: ioctls without CAP_IOCTL", func)); } static void fdgrowtable_exp(struct filedesc *fdp, int nfd) { int nfd1; FILEDESC_XLOCK_ASSERT(fdp); nfd1 = fdp->fd_nfiles * 2; if (nfd1 < nfd) nfd1 = nfd; fdgrowtable(fdp, nfd1); } /* * Grow the file table to accommodate (at least) nfd descriptors. */ static void fdgrowtable(struct filedesc *fdp, int nfd) { struct filedesc0 *fdp0; struct freetable *ft; struct fdescenttbl *ntable; struct fdescenttbl *otable; int nnfiles, onfiles; NDSLOTTYPE *nmap, *omap; KASSERT(fdp->fd_nfiles > 0, ("zero-length file table")); /* save old values */ onfiles = fdp->fd_nfiles; otable = fdp->fd_files; omap = fdp->fd_map; /* compute the size of the new table */ nnfiles = NDSLOTS(nfd) * NDENTRIES; /* round up */ if (nnfiles <= onfiles) /* the table is already large enough */ return; /* * Allocate a new table. We need enough space for the number of * entries, file entries themselves and the struct freetable we will use * when we decommission the table and place it on the freelist. * We place the struct freetable in the middle so we don't have * to worry about padding. */ ntable = malloc(offsetof(struct fdescenttbl, fdt_ofiles) + nnfiles * sizeof(ntable->fdt_ofiles[0]) + sizeof(struct freetable), M_FILEDESC, M_ZERO | M_WAITOK); /* copy the old data */ ntable->fdt_nfiles = nnfiles; memcpy(ntable->fdt_ofiles, otable->fdt_ofiles, onfiles * sizeof(ntable->fdt_ofiles[0])); /* * Allocate a new map only if the old is not large enough. It will * grow at a slower rate than the table as it can map more * entries than the table can hold. */ if (NDSLOTS(nnfiles) > NDSLOTS(onfiles)) { nmap = malloc(NDSLOTS(nnfiles) * NDSLOTSIZE, M_FILEDESC, M_ZERO | M_WAITOK); /* copy over the old data and update the pointer */ memcpy(nmap, omap, NDSLOTS(onfiles) * sizeof(*omap)); fdp->fd_map = nmap; } /* * Make sure that ntable is correctly initialized before we replace * fd_files poiner. Otherwise fget_unlocked() may see inconsistent * data. */ atomic_store_rel_ptr((volatile void *)&fdp->fd_files, (uintptr_t)ntable); /* * Free the old file table when not shared by other threads or processes. * The old file table is considered to be shared when either are true: * - The process has more than one thread. * - The file descriptor table has been shared via fdshare(). * * When shared, the old file table will be placed on a freelist * which will be processed when the struct filedesc is released. * * Note that if onfiles == NDFILE, we're dealing with the original * static allocation contained within (struct filedesc0 *)fdp, * which must not be freed. */ if (onfiles > NDFILE) { /* * Note we may be called here from fdinit while allocating a * table for a new process in which case ->p_fd points * elsewhere. */ if (curproc->p_fd != fdp || FILEDESC_IS_ONLY_USER(fdp)) { free(otable, M_FILEDESC); } else { ft = (struct freetable *)&otable->fdt_ofiles[onfiles]; fdp0 = (struct filedesc0 *)fdp; ft->ft_table = otable; SLIST_INSERT_HEAD(&fdp0->fd_free, ft, ft_next); } } /* * The map does not have the same possibility of threads still * holding references to it. So always free it as long as it * does not reference the original static allocation. */ if (NDSLOTS(onfiles) > NDSLOTS(NDFILE)) free(omap, M_FILEDESC); } /* * Allocate a file descriptor for the process. */ int fdalloc(struct thread *td, int minfd, int *result) { struct proc *p = td->td_proc; struct filedesc *fdp = p->p_fd; int fd, maxfd, allocfd; #ifdef RACCT int error; #endif FILEDESC_XLOCK_ASSERT(fdp); if (fdp->fd_freefile > minfd) minfd = fdp->fd_freefile; maxfd = getmaxfd(td); /* * Search the bitmap for a free descriptor starting at minfd. * If none is found, grow the file table. */ fd = fd_first_free(fdp, minfd, fdp->fd_nfiles); if (__predict_false(fd >= maxfd)) return (EMFILE); if (__predict_false(fd >= fdp->fd_nfiles)) { allocfd = min(fd * 2, maxfd); #ifdef RACCT if (RACCT_ENABLED()) { error = racct_set_unlocked(p, RACCT_NOFILE, allocfd); if (error != 0) return (EMFILE); } #endif /* * fd is already equal to first free descriptor >= minfd, so * we only need to grow the table and we are done. */ fdgrowtable_exp(fdp, allocfd); } /* * Perform some sanity checks, then mark the file descriptor as * used and return it to the caller. */ KASSERT(fd >= 0 && fd < min(maxfd, fdp->fd_nfiles), ("invalid descriptor %d", fd)); KASSERT(!fdisused(fdp, fd), ("fd_first_free() returned non-free descriptor")); KASSERT(fdp->fd_ofiles[fd].fde_file == NULL, ("file descriptor isn't free")); fdused(fdp, fd); *result = fd; return (0); } /* * Allocate n file descriptors for the process. */ int fdallocn(struct thread *td, int minfd, int *fds, int n) { struct proc *p = td->td_proc; struct filedesc *fdp = p->p_fd; int i; FILEDESC_XLOCK_ASSERT(fdp); for (i = 0; i < n; i++) if (fdalloc(td, 0, &fds[i]) != 0) break; if (i < n) { for (i--; i >= 0; i--) fdunused(fdp, fds[i]); return (EMFILE); } return (0); } /* * Create a new open file structure and allocate a file descriptor for the * process that refers to it. We add one reference to the file for the * descriptor table and one reference for resultfp. This is to prevent us * being preempted and the entry in the descriptor table closed after we * release the FILEDESC lock. */ int falloc_caps(struct thread *td, struct file **resultfp, int *resultfd, int flags, struct filecaps *fcaps) { struct file *fp; int error, fd; MPASS(resultfp != NULL); MPASS(resultfd != NULL); error = _falloc_noinstall(td, &fp, 2); if (__predict_false(error != 0)) { return (error); } error = finstall_refed(td, fp, &fd, flags, fcaps); if (__predict_false(error != 0)) { falloc_abort(td, fp); return (error); } *resultfp = fp; *resultfd = fd; return (0); } /* * Create a new open file structure without allocating a file descriptor. */ int _falloc_noinstall(struct thread *td, struct file **resultfp, u_int n) { struct file *fp; int maxuserfiles = maxfiles - (maxfiles / 20); int openfiles_new; static struct timeval lastfail; static int curfail; KASSERT(resultfp != NULL, ("%s: resultfp == NULL", __func__)); MPASS(n > 0); openfiles_new = atomic_fetchadd_int(&openfiles, 1) + 1; if ((openfiles_new >= maxuserfiles && priv_check(td, PRIV_MAXFILES) != 0) || openfiles_new >= maxfiles) { atomic_subtract_int(&openfiles, 1); if (ppsratecheck(&lastfail, &curfail, 1)) { printf("kern.maxfiles limit exceeded by uid %i, (%s) " "please see tuning(7).\n", td->td_ucred->cr_ruid, td->td_proc->p_comm); } return (ENFILE); } fp = uma_zalloc(file_zone, M_WAITOK); bzero(fp, sizeof(*fp)); refcount_init(&fp->f_count, n); fp->f_cred = crhold(td->td_ucred); fp->f_ops = &badfileops; *resultfp = fp; return (0); } void falloc_abort(struct thread *td, struct file *fp) { /* * For assertion purposes. */ refcount_init(&fp->f_count, 0); _fdrop(fp, td); } /* * Install a file in a file descriptor table. */ void _finstall(struct filedesc *fdp, struct file *fp, int fd, int flags, struct filecaps *fcaps) { struct filedescent *fde; MPASS(fp != NULL); if (fcaps != NULL) filecaps_validate(fcaps, __func__); FILEDESC_XLOCK_ASSERT(fdp); fde = &fdp->fd_ofiles[fd]; #ifdef CAPABILITIES seqc_write_begin(&fde->fde_seqc); #endif fde->fde_file = fp; fde->fde_flags = (flags & O_CLOEXEC) != 0 ? UF_EXCLOSE : 0; if (fcaps != NULL) filecaps_move(fcaps, &fde->fde_caps); else filecaps_fill(&fde->fde_caps); #ifdef CAPABILITIES seqc_write_end(&fde->fde_seqc); #endif } int finstall_refed(struct thread *td, struct file *fp, int *fd, int flags, struct filecaps *fcaps) { struct filedesc *fdp = td->td_proc->p_fd; int error; MPASS(fd != NULL); FILEDESC_XLOCK(fdp); error = fdalloc(td, 0, fd); if (__predict_true(error == 0)) { _finstall(fdp, fp, *fd, flags, fcaps); } FILEDESC_XUNLOCK(fdp); return (error); } int finstall(struct thread *td, struct file *fp, int *fd, int flags, struct filecaps *fcaps) { int error; MPASS(fd != NULL); if (!fhold(fp)) return (EBADF); error = finstall_refed(td, fp, fd, flags, fcaps); if (__predict_false(error != 0)) { fdrop(fp, td); } return (error); } /* * Build a new filedesc structure from another. * * If fdp is not NULL, return with it shared locked. */ struct filedesc * fdinit(void) { struct filedesc0 *newfdp0; struct filedesc *newfdp; newfdp0 = uma_zalloc(filedesc0_zone, M_WAITOK | M_ZERO); newfdp = &newfdp0->fd_fd; /* Create the file descriptor table. */ FILEDESC_LOCK_INIT(newfdp); refcount_init(&newfdp->fd_refcnt, 1); refcount_init(&newfdp->fd_holdcnt, 1); newfdp->fd_map = newfdp0->fd_dmap; newfdp->fd_files = (struct fdescenttbl *)&newfdp0->fd_dfiles; newfdp->fd_files->fdt_nfiles = NDFILE; return (newfdp); } /* * Build a pwddesc structure from another. * Copy the current, root, and jail root vnode references. * * If pdp is not NULL, return with it shared locked. */ struct pwddesc * pdinit(struct pwddesc *pdp, bool keeplock) { struct pwddesc *newpdp; struct pwd *newpwd; newpdp = malloc(sizeof(*newpdp), M_PWDDESC, M_WAITOK | M_ZERO); PWDDESC_LOCK_INIT(newpdp); refcount_init(&newpdp->pd_refcount, 1); newpdp->pd_cmask = CMASK; if (pdp == NULL) { newpwd = pwd_alloc(); smr_serialized_store(&newpdp->pd_pwd, newpwd, true); return (newpdp); } PWDDESC_XLOCK(pdp); newpwd = pwd_hold_pwddesc(pdp); smr_serialized_store(&newpdp->pd_pwd, newpwd, true); if (!keeplock) PWDDESC_XUNLOCK(pdp); return (newpdp); } /* * Hold either filedesc or pwddesc of the passed process. * * The process lock is used to synchronize against the target exiting and * freeing the data. * * Clearing can be ilustrated in 3 steps: * 1. set the pointer to NULL. Either routine can race against it, hence * atomic_load_ptr. * 2. observe the process lock as not taken. Until then fdhold/pdhold can * race to either still see the pointer or find NULL. It is still safe to * grab a reference as clearing is stalled. * 3. after the lock is observed as not taken, any fdhold/pdhold calls are * guaranteed to see NULL, making it safe to finish clearing */ static struct filedesc * fdhold(struct proc *p) { struct filedesc *fdp; PROC_LOCK_ASSERT(p, MA_OWNED); fdp = atomic_load_ptr(&p->p_fd); if (fdp != NULL) refcount_acquire(&fdp->fd_holdcnt); return (fdp); } static struct pwddesc * pdhold(struct proc *p) { struct pwddesc *pdp; PROC_LOCK_ASSERT(p, MA_OWNED); pdp = atomic_load_ptr(&p->p_pd); if (pdp != NULL) refcount_acquire(&pdp->pd_refcount); return (pdp); } static void fddrop(struct filedesc *fdp) { if (refcount_load(&fdp->fd_holdcnt) > 1) { if (refcount_release(&fdp->fd_holdcnt) == 0) return; } FILEDESC_LOCK_DESTROY(fdp); uma_zfree(filedesc0_zone, fdp); } static void pddrop(struct pwddesc *pdp) { struct pwd *pwd; if (refcount_release_if_not_last(&pdp->pd_refcount)) return; PWDDESC_XLOCK(pdp); if (refcount_release(&pdp->pd_refcount) == 0) { PWDDESC_XUNLOCK(pdp); return; } pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); pwd_set(pdp, NULL); PWDDESC_XUNLOCK(pdp); pwd_drop(pwd); PWDDESC_LOCK_DESTROY(pdp); free(pdp, M_PWDDESC); } /* * Share a filedesc structure. */ struct filedesc * fdshare(struct filedesc *fdp) { refcount_acquire(&fdp->fd_refcnt); return (fdp); } /* * Share a pwddesc structure. */ struct pwddesc * pdshare(struct pwddesc *pdp) { refcount_acquire(&pdp->pd_refcount); return (pdp); } /* * Unshare a filedesc structure, if necessary by making a copy */ void fdunshare(struct thread *td) { struct filedesc *tmp; struct proc *p = td->td_proc; if (refcount_load(&p->p_fd->fd_refcnt) == 1) return; tmp = fdcopy(p->p_fd); fdescfree(td); p->p_fd = tmp; } /* * Unshare a pwddesc structure. */ void pdunshare(struct thread *td) { struct pwddesc *pdp; struct proc *p; p = td->td_proc; /* Not shared. */ if (refcount_load(&p->p_pd->pd_refcount) == 1) return; pdp = pdcopy(p->p_pd); pdescfree(td); p->p_pd = pdp; } /* * Copy a filedesc structure. A NULL pointer in returns a NULL reference, * this is to ease callers, not catch errors. */ struct filedesc * fdcopy(struct filedesc *fdp) { struct filedesc *newfdp; struct filedescent *nfde, *ofde; int i, lastfile; MPASS(fdp != NULL); newfdp = fdinit(); FILEDESC_SLOCK(fdp); for (;;) { lastfile = fdlastfile(fdp); if (lastfile < newfdp->fd_nfiles) break; FILEDESC_SUNLOCK(fdp); fdgrowtable(newfdp, lastfile + 1); FILEDESC_SLOCK(fdp); } /* copy all passable descriptors (i.e. not kqueue) */ newfdp->fd_freefile = fdp->fd_freefile; FILEDESC_FOREACH_FDE(fdp, i, ofde) { if ((ofde->fde_file->f_ops->fo_flags & DFLAG_PASSABLE) == 0 || !fhold(ofde->fde_file)) { if (newfdp->fd_freefile == fdp->fd_freefile) newfdp->fd_freefile = i; continue; } nfde = &newfdp->fd_ofiles[i]; *nfde = *ofde; filecaps_copy(&ofde->fde_caps, &nfde->fde_caps, true); fdused_init(newfdp, i); } MPASS(newfdp->fd_freefile != -1); FILEDESC_SUNLOCK(fdp); return (newfdp); } /* * Copy a pwddesc structure. */ struct pwddesc * pdcopy(struct pwddesc *pdp) { struct pwddesc *newpdp; MPASS(pdp != NULL); newpdp = pdinit(pdp, true); newpdp->pd_cmask = pdp->pd_cmask; PWDDESC_XUNLOCK(pdp); return (newpdp); } /* * Clear POSIX style locks. This is only used when fdp looses a reference (i.e. * one of processes using it exits) and the table used to be shared. */ static void fdclearlocks(struct thread *td) { struct filedesc *fdp; struct filedesc_to_leader *fdtol; struct flock lf; struct file *fp; struct proc *p; struct vnode *vp; int i; p = td->td_proc; fdp = p->p_fd; fdtol = p->p_fdtol; MPASS(fdtol != NULL); FILEDESC_XLOCK(fdp); KASSERT(fdtol->fdl_refcount > 0, ("filedesc_to_refcount botch: fdl_refcount=%d", fdtol->fdl_refcount)); if (fdtol->fdl_refcount == 1 && (p->p_leader->p_flag & P_ADVLOCK) != 0) { FILEDESC_FOREACH_FP(fdp, i, fp) { if (fp->f_type != DTYPE_VNODE || !fhold(fp)) continue; FILEDESC_XUNLOCK(fdp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; vp = fp->f_vnode; (void) VOP_ADVLOCK(vp, (caddr_t)p->p_leader, F_UNLCK, &lf, F_POSIX); FILEDESC_XLOCK(fdp); fdrop(fp, td); } } retry: if (fdtol->fdl_refcount == 1) { if (fdp->fd_holdleaderscount > 0 && (p->p_leader->p_flag & P_ADVLOCK) != 0) { /* * close() or kern_dup() has cleared a reference * in a shared file descriptor table. */ fdp->fd_holdleaderswakeup = 1; sx_sleep(&fdp->fd_holdleaderscount, FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); goto retry; } if (fdtol->fdl_holdcount > 0) { /* * Ensure that fdtol->fdl_leader remains * valid in closef(). */ fdtol->fdl_wakeup = 1; sx_sleep(fdtol, FILEDESC_LOCK(fdp), PLOCK, "fdlhold", 0); goto retry; } } fdtol->fdl_refcount--; if (fdtol->fdl_refcount == 0 && fdtol->fdl_holdcount == 0) { fdtol->fdl_next->fdl_prev = fdtol->fdl_prev; fdtol->fdl_prev->fdl_next = fdtol->fdl_next; } else fdtol = NULL; p->p_fdtol = NULL; FILEDESC_XUNLOCK(fdp); if (fdtol != NULL) free(fdtol, M_FILEDESC_TO_LEADER); } /* * Release a filedesc structure. */ static void fdescfree_fds(struct thread *td, struct filedesc *fdp) { struct filedesc0 *fdp0; struct freetable *ft, *tft; struct filedescent *fde; struct file *fp; int i; KASSERT(refcount_load(&fdp->fd_refcnt) == 0, ("%s: fd table %p carries references", __func__, fdp)); /* * Serialize with threads iterating over the table, if any. */ if (refcount_load(&fdp->fd_holdcnt) > 1) { FILEDESC_XLOCK(fdp); FILEDESC_XUNLOCK(fdp); } FILEDESC_FOREACH_FDE(fdp, i, fde) { fp = fde->fde_file; fdefree_last(fde); (void) closef(fp, td); } if (NDSLOTS(fdp->fd_nfiles) > NDSLOTS(NDFILE)) free(fdp->fd_map, M_FILEDESC); if (fdp->fd_nfiles > NDFILE) free(fdp->fd_files, M_FILEDESC); fdp0 = (struct filedesc0 *)fdp; SLIST_FOREACH_SAFE(ft, &fdp0->fd_free, ft_next, tft) free(ft->ft_table, M_FILEDESC); fddrop(fdp); } void fdescfree(struct thread *td) { struct proc *p; struct filedesc *fdp; p = td->td_proc; fdp = p->p_fd; MPASS(fdp != NULL); #ifdef RACCT if (RACCT_ENABLED()) racct_set_unlocked(p, RACCT_NOFILE, 0); #endif if (p->p_fdtol != NULL) fdclearlocks(td); /* * Check fdhold for an explanation. */ atomic_store_ptr(&p->p_fd, NULL); atomic_thread_fence_seq_cst(); PROC_WAIT_UNLOCKED(p); if (refcount_release(&fdp->fd_refcnt) == 0) return; fdescfree_fds(td, fdp); } void pdescfree(struct thread *td) { struct proc *p; struct pwddesc *pdp; p = td->td_proc; pdp = p->p_pd; MPASS(pdp != NULL); /* * Check pdhold for an explanation. */ atomic_store_ptr(&p->p_pd, NULL); atomic_thread_fence_seq_cst(); PROC_WAIT_UNLOCKED(p); pddrop(pdp); } /* * For setugid programs, we don't want to people to use that setugidness * to generate error messages which write to a file which otherwise would * otherwise be off-limits to the process. We check for filesystems where * the vnode can change out from under us after execve (like [lin]procfs). * * Since fdsetugidsafety calls this only for fd 0, 1 and 2, this check is * sufficient. We also don't check for setugidness since we know we are. */ static bool is_unsafe(struct file *fp) { struct vnode *vp; if (fp->f_type != DTYPE_VNODE) return (false); vp = fp->f_vnode; return ((vp->v_vflag & VV_PROCDEP) != 0); } /* * Make this setguid thing safe, if at all possible. */ void fdsetugidsafety(struct thread *td) { struct filedesc *fdp; struct file *fp; int i; fdp = td->td_proc->p_fd; KASSERT(refcount_load(&fdp->fd_refcnt) == 1, ("the fdtable should not be shared")); MPASS(fdp->fd_nfiles >= 3); for (i = 0; i <= 2; i++) { fp = fdp->fd_ofiles[i].fde_file; if (fp != NULL && is_unsafe(fp)) { FILEDESC_XLOCK(fdp); knote_fdclose(td, i); /* * NULL-out descriptor prior to close to avoid * a race while close blocks. */ fdfree(fdp, i); FILEDESC_XUNLOCK(fdp); (void) closef(fp, td); } } } /* * If a specific file object occupies a specific file descriptor, close the * file descriptor entry and drop a reference on the file object. This is a * convenience function to handle a subsequent error in a function that calls * falloc() that handles the race that another thread might have closed the * file descriptor out from under the thread creating the file object. */ void fdclose(struct thread *td, struct file *fp, int idx) { struct filedesc *fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); if (fdp->fd_ofiles[idx].fde_file == fp) { fdfree(fdp, idx); FILEDESC_XUNLOCK(fdp); fdrop(fp, td); } else FILEDESC_XUNLOCK(fdp); } /* * Close any files on exec? */ void fdcloseexec(struct thread *td) { struct filedesc *fdp; struct filedescent *fde; struct file *fp; int i; fdp = td->td_proc->p_fd; KASSERT(refcount_load(&fdp->fd_refcnt) == 1, ("the fdtable should not be shared")); FILEDESC_FOREACH_FDE(fdp, i, fde) { fp = fde->fde_file; if (fp->f_type == DTYPE_MQUEUE || (fde->fde_flags & UF_EXCLOSE)) { FILEDESC_XLOCK(fdp); fdfree(fdp, i); (void) closefp(fdp, i, fp, td, false, false); FILEDESC_UNLOCK_ASSERT(fdp); } } } /* * It is unsafe for set[ug]id processes to be started with file * descriptors 0..2 closed, as these descriptors are given implicit * significance in the Standard C library. fdcheckstd() will create a * descriptor referencing /dev/null for each of stdin, stdout, and * stderr that is not already open. */ int fdcheckstd(struct thread *td) { struct filedesc *fdp; register_t save; int i, error, devnull; fdp = td->td_proc->p_fd; KASSERT(refcount_load(&fdp->fd_refcnt) == 1, ("the fdtable should not be shared")); MPASS(fdp->fd_nfiles >= 3); devnull = -1; for (i = 0; i <= 2; i++) { if (fdp->fd_ofiles[i].fde_file != NULL) continue; save = td->td_retval[0]; if (devnull != -1) { error = kern_dup(td, FDDUP_FIXED, 0, devnull, i); } else { error = kern_openat(td, AT_FDCWD, "/dev/null", UIO_SYSSPACE, O_RDWR, 0); if (error == 0) { devnull = td->td_retval[0]; KASSERT(devnull == i, ("we didn't get our fd")); } } td->td_retval[0] = save; if (error != 0) return (error); } return (0); } /* * Internal form of close. Decrement reference count on file structure. * Note: td may be NULL when closing a file that was being passed in a * message. */ int closef(struct file *fp, struct thread *td) { struct vnode *vp; struct flock lf; struct filedesc_to_leader *fdtol; struct filedesc *fdp; MPASS(td != NULL); /* * POSIX record locking dictates that any close releases ALL * locks owned by this process. This is handled by setting * a flag in the unlock to free ONLY locks obeying POSIX * semantics, and not to free BSD-style file locks. * If the descriptor was in a message, POSIX-style locks * aren't passed with the descriptor, and the thread pointer * will be NULL. Callers should be careful only to pass a * NULL thread pointer when there really is no owning * context that might have locks, or the locks will be * leaked. */ if (fp->f_type == DTYPE_VNODE) { vp = fp->f_vnode; if ((td->td_proc->p_leader->p_flag & P_ADVLOCK) != 0) { lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)td->td_proc->p_leader, F_UNLCK, &lf, F_POSIX); } fdtol = td->td_proc->p_fdtol; if (fdtol != NULL) { /* * Handle special case where file descriptor table is * shared between multiple process leaders. */ fdp = td->td_proc->p_fd; FILEDESC_XLOCK(fdp); for (fdtol = fdtol->fdl_next; fdtol != td->td_proc->p_fdtol; fdtol = fdtol->fdl_next) { if ((fdtol->fdl_leader->p_flag & P_ADVLOCK) == 0) continue; fdtol->fdl_holdcount++; FILEDESC_XUNLOCK(fdp); lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; vp = fp->f_vnode; (void) VOP_ADVLOCK(vp, (caddr_t)fdtol->fdl_leader, F_UNLCK, &lf, F_POSIX); FILEDESC_XLOCK(fdp); fdtol->fdl_holdcount--; if (fdtol->fdl_holdcount == 0 && fdtol->fdl_wakeup != 0) { fdtol->fdl_wakeup = 0; wakeup(fdtol); } } FILEDESC_XUNLOCK(fdp); } } return (fdrop_close(fp, td)); } /* * Hack for file descriptor passing code. */ void closef_nothread(struct file *fp) { fdrop(fp, NULL); } /* * Initialize the file pointer with the specified properties. * * The ops are set with release semantics to be certain that the flags, type, * and data are visible when ops is. This is to prevent ops methods from being * called with bad data. */ void finit(struct file *fp, u_int flag, short type, void *data, struct fileops *ops) { fp->f_data = data; fp->f_flag = flag; fp->f_type = type; atomic_store_rel_ptr((volatile uintptr_t *)&fp->f_ops, (uintptr_t)ops); } void finit_vnode(struct file *fp, u_int flag, void *data, struct fileops *ops) { fp->f_seqcount[UIO_READ] = 1; fp->f_seqcount[UIO_WRITE] = 1; finit(fp, (flag & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, data, ops); } int fget_cap_noref(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { struct filedescent *fde; int error; FILEDESC_LOCK_ASSERT(fdp); *fpp = NULL; fde = fdeget_noref(fdp, fd); if (fde == NULL) { error = EBADF; goto out; } #ifdef CAPABILITIES error = cap_check(cap_rights_fde_inline(fde), needrightsp); if (error != 0) goto out; #endif if (havecapsp != NULL) filecaps_copy(&fde->fde_caps, havecapsp, true); *fpp = fde->fde_file; error = 0; out: return (error); } #ifdef CAPABILITIES int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { struct filedesc *fdp = td->td_proc->p_fd; int error; struct file *fp; seqc_t seq; *fpp = NULL; for (;;) { error = fget_unlocked_seq(td, fd, needrightsp, &fp, &seq); if (error != 0) return (error); if (havecapsp != NULL) { if (!filecaps_copy(&fdp->fd_ofiles[fd].fde_caps, havecapsp, false)) { fdrop(fp, td); goto get_locked; } } if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } *fpp = fp; return (0); get_locked: FILEDESC_SLOCK(fdp); error = fget_cap_noref(fdp, fd, needrightsp, fpp, havecapsp); if (error == 0 && !fhold(*fpp)) error = EBADF; FILEDESC_SUNLOCK(fdp); return (error); } #else int fget_cap(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, struct filecaps *havecapsp) { int error; error = fget_unlocked(td, fd, needrightsp, fpp); if (havecapsp != NULL && error == 0) filecaps_fill(havecapsp); return (error); } #endif #ifdef CAPABILITIES int fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) { const struct filedescent *fde; const struct fdescenttbl *fdt; struct filedesc *fdp; struct file *fp; struct vnode *vp; const cap_rights_t *haverights; cap_rights_t rights; seqc_t seq; VFS_SMR_ASSERT_ENTERED(); rights = *ndp->ni_rightsneeded; cap_rights_set_one(&rights, CAP_LOOKUP); fdp = curproc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = cap_rights_fde_inline(fde); fp = fde->fde_file; if (__predict_false(fp == NULL)) return (EAGAIN); if (__predict_false(cap_check_inline_transient(haverights, &rights))) return (EAGAIN); *fsearch = ((fp->f_flag & FSEARCH) != 0); vp = fp->f_vnode; if (__predict_false(vp == NULL)) { return (EAGAIN); } if (!filecaps_copy(&fde->fde_caps, &ndp->ni_filecaps, false)) { return (EAGAIN); } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) return (EAGAIN); /* * If file descriptor doesn't have all rights, * all lookups relative to it must also be * strictly relative. * * Not yet supported by fast path. */ CAP_ALL(&rights); if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || ndp->ni_filecaps.fc_nioctls != -1) { #ifdef notyet ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; #else return (EAGAIN); #endif } *vpp = vp; return (0); } #else int fgetvp_lookup_smr(int fd, struct nameidata *ndp, struct vnode **vpp, bool *fsearch) { const struct fdescenttbl *fdt; struct filedesc *fdp; struct file *fp; struct vnode *vp; VFS_SMR_ASSERT_ENTERED(); fdp = curproc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); fp = fdt->fdt_ofiles[fd].fde_file; if (__predict_false(fp == NULL)) return (EAGAIN); *fsearch = ((fp->f_flag & FSEARCH) != 0); vp = fp->f_vnode; if (__predict_false(vp == NULL || vp->v_type != VDIR)) { return (EAGAIN); } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) return (EAGAIN); filecaps_fill(&ndp->ni_filecaps); *vpp = vp; return (0); } #endif int fgetvp_lookup(int fd, struct nameidata *ndp, struct vnode **vpp) { struct thread *td; struct file *fp; struct vnode *vp; struct componentname *cnp; cap_rights_t rights; int error; td = curthread; rights = *ndp->ni_rightsneeded; cap_rights_set_one(&rights, CAP_LOOKUP); cnp = &ndp->ni_cnd; error = fget_cap(td, ndp->ni_dirfd, &rights, &fp, &ndp->ni_filecaps); if (__predict_false(error != 0)) return (error); if (__predict_false(fp->f_ops == &badfileops)) { error = EBADF; goto out_free; } vp = fp->f_vnode; if (__predict_false(vp == NULL)) { error = ENOTDIR; goto out_free; } vrefact(vp); /* * XXX does not check for VDIR, handled by namei_setup */ if ((fp->f_flag & FSEARCH) != 0) cnp->cn_flags |= NOEXECCHECK; fdrop(fp, td); #ifdef CAPABILITIES /* * If file descriptor doesn't have all rights, * all lookups relative to it must also be * strictly relative. */ CAP_ALL(&rights); if (!cap_rights_contains(&ndp->ni_filecaps.fc_rights, &rights) || ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL || ndp->ni_filecaps.fc_nioctls != -1) { ndp->ni_lcf |= NI_LCF_STRICTRELATIVE; ndp->ni_resflags |= NIRES_STRICTREL; } #endif /* * TODO: avoid copying ioctl caps if it can be helped to begin with */ if ((cnp->cn_flags & WANTIOCTLCAPS) == 0) filecaps_free_ioctl(&ndp->ni_filecaps); *vpp = vp; return (0); out_free: filecaps_free(&ndp->ni_filecaps); fdrop(fp, td); return (error); } /* * Fetch the descriptor locklessly. * * We avoid fdrop() races by never raising a refcount above 0. To accomplish * this we have to use a cmpset loop rather than an atomic_add. The descriptor * must be re-verified once we acquire a reference to be certain that the * identity is still correct and we did not lose a race due to preemption. * * Force a reload of fdt when looping. Another thread could reallocate * the table before this fd was closed, so it is possible that there is * a stale fp pointer in cached version. */ #ifdef CAPABILITIES static int fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp) { struct filedesc *fdp; const struct filedescent *fde; const struct fdescenttbl *fdt; struct file *fp; seqc_t seq; cap_rights_t haverights; int error; fdp = td->td_proc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); for (;;) { seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = *cap_rights_fde_inline(fde); fp = fde->fde_file; if (__predict_false(fp == NULL)) { if (seqc_consistent(fd_seqc(fdt, fd), seq)) return (EBADF); fdt = atomic_load_ptr(&fdp->fd_files); continue; } error = cap_check_inline(&haverights, needrightsp); if (__predict_false(error != 0)) { if (seqc_consistent(fd_seqc(fdt, fd), seq)) return (error); fdt = atomic_load_ptr(&fdp->fd_files); continue; } if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { fdt = atomic_load_ptr(&fdp->fd_files); continue; } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; if (seqc_consistent_no_fence(fd_seqc(fdt, fd), seq)) break; fdrop(fp, td); } *fpp = fp; if (seqp != NULL) { *seqp = seq; } return (0); } #else static int fget_unlocked_seq(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp, seqc_t *seqp __unused) { struct filedesc *fdp; const struct fdescenttbl *fdt; struct file *fp; fdp = td->td_proc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) return (EBADF); for (;;) { fp = fdt->fdt_ofiles[fd].fde_file; if (__predict_false(fp == NULL)) return (EBADF); if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) { fdt = atomic_load_ptr(&fdp->fd_files); continue; } /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; if (__predict_true(fp == fdt->fdt_ofiles[fd].fde_file)) break; fdrop(fp, td); } *fpp = fp; return (0); } #endif /* * See the comments in fget_unlocked_seq for an explanation of how this works. * * This is a simplified variant which bails out to the aforementioned routine * if anything goes wrong. In practice this only happens when userspace is * racing with itself. */ int fget_unlocked(struct thread *td, int fd, cap_rights_t *needrightsp, struct file **fpp) { struct filedesc *fdp; #ifdef CAPABILITIES const struct filedescent *fde; #endif const struct fdescenttbl *fdt; struct file *fp; #ifdef CAPABILITIES seqc_t seq; const cap_rights_t *haverights; #endif fdp = td->td_proc->p_fd; fdt = fdp->fd_files; if (__predict_false((u_int)fd >= fdt->fdt_nfiles)) { *fpp = NULL; return (EBADF); } #ifdef CAPABILITIES seq = seqc_read_notmodify(fd_seqc(fdt, fd)); fde = &fdt->fdt_ofiles[fd]; haverights = cap_rights_fde_inline(fde); fp = fde->fde_file; #else fp = fdt->fdt_ofiles[fd].fde_file; #endif if (__predict_false(fp == NULL)) goto out_fallback; #ifdef CAPABILITIES if (__predict_false(cap_check_inline_transient(haverights, needrightsp))) goto out_fallback; #endif if (__predict_false(!refcount_acquire_if_not_zero(&fp->f_count))) goto out_fallback; /* * Use an acquire barrier to force re-reading of fdt so it is * refreshed for verification. */ atomic_thread_fence_acq(); fdt = fdp->fd_files; #ifdef CAPABILITIES if (__predict_false(!seqc_consistent_no_fence(fd_seqc(fdt, fd), seq))) #else if (__predict_false(fp != fdt->fdt_ofiles[fd].fde_file)) #endif goto out_fdrop; *fpp = fp; return (0); out_fdrop: fdrop(fp, td); out_fallback: *fpp = NULL; return (fget_unlocked_seq(td, fd, needrightsp, fpp, NULL)); } /* * Translate fd -> file when the caller guarantees the file descriptor table * can't be changed by others. * * Note this does not mean the file object itself is only visible to the caller, * merely that it wont disappear without having to be referenced. * * Must be paired with fput_only_user. */ #ifdef CAPABILITIES int fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp) { const struct filedescent *fde; const struct fdescenttbl *fdt; const cap_rights_t *haverights; struct file *fp; int error; MPASS(FILEDESC_IS_ONLY_USER(fdp)); *fpp = NULL; if (__predict_false(fd >= fdp->fd_nfiles)) return (EBADF); fdt = fdp->fd_files; fde = &fdt->fdt_ofiles[fd]; fp = fde->fde_file; if (__predict_false(fp == NULL)) return (EBADF); MPASS(refcount_load(&fp->f_count) > 0); haverights = cap_rights_fde_inline(fde); error = cap_check_inline(haverights, needrightsp); if (__predict_false(error != 0)) return (error); *fpp = fp; return (0); } #else int fget_only_user(struct filedesc *fdp, int fd, cap_rights_t *needrightsp, struct file **fpp) { struct file *fp; MPASS(FILEDESC_IS_ONLY_USER(fdp)); *fpp = NULL; if (__predict_false(fd >= fdp->fd_nfiles)) return (EBADF); fp = fdp->fd_ofiles[fd].fde_file; if (__predict_false(fp == NULL)) return (EBADF); MPASS(refcount_load(&fp->f_count) > 0); *fpp = fp; return (0); } #endif /* * Extract the file pointer associated with the specified descriptor for the * current user process. * * If the descriptor doesn't exist or doesn't match 'flags', EBADF is * returned. * * File's rights will be checked against the capability rights mask. * * If an error occurred the non-zero error is returned and *fpp is set to * NULL. Otherwise *fpp is held and set and zero is returned. Caller is * responsible for fdrop(). */ static __inline int _fget(struct thread *td, int fd, struct file **fpp, int flags, cap_rights_t *needrightsp) { struct file *fp; int error; *fpp = NULL; error = fget_unlocked(td, fd, needrightsp, &fp); if (__predict_false(error != 0)) return (error); if (__predict_false(fp->f_ops == &badfileops)) { fdrop(fp, td); return (EBADF); } /* * FREAD and FWRITE failure return EBADF as per POSIX. */ error = 0; switch (flags) { case FREAD: case FWRITE: if ((fp->f_flag & flags) == 0) error = EBADF; break; case FEXEC: if (fp->f_ops != &path_fileops && ((fp->f_flag & (FREAD | FEXEC)) == 0 || (fp->f_flag & FWRITE) != 0)) error = EBADF; break; case 0: break; default: KASSERT(0, ("wrong flags")); } if (error != 0) { fdrop(fp, td); return (error); } *fpp = fp; return (0); } int fget(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, 0, rightsp)); } int fget_mmap(struct thread *td, int fd, cap_rights_t *rightsp, vm_prot_t *maxprotp, struct file **fpp) { int error; #ifndef CAPABILITIES error = _fget(td, fd, fpp, 0, rightsp); if (maxprotp != NULL) *maxprotp = VM_PROT_ALL; return (error); #else cap_rights_t fdrights; struct filedesc *fdp; struct file *fp; seqc_t seq; *fpp = NULL; fdp = td->td_proc->p_fd; MPASS(cap_rights_is_set(rightsp, CAP_MMAP)); for (;;) { error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq); if (__predict_false(error != 0)) return (error); if (__predict_false(fp->f_ops == &badfileops)) { fdrop(fp, td); return (EBADF); } if (maxprotp != NULL) fdrights = *cap_rights(fdp, fd); if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } /* * If requested, convert capability rights to access flags. */ if (maxprotp != NULL) *maxprotp = cap_rights_to_vmprot(&fdrights); *fpp = fp; return (0); #endif } int fget_read(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, FREAD, rightsp)); } int fget_write(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp) { return (_fget(td, fd, fpp, FWRITE, rightsp)); } int fget_fcntl(struct thread *td, int fd, cap_rights_t *rightsp, int needfcntl, struct file **fpp) { #ifndef CAPABILITIES return (fget_unlocked(td, fd, rightsp, fpp)); #else struct filedesc *fdp = td->td_proc->p_fd; struct file *fp; int error; seqc_t seq; *fpp = NULL; MPASS(cap_rights_is_set(rightsp, CAP_FCNTL)); for (;;) { error = fget_unlocked_seq(td, fd, rightsp, &fp, &seq); if (error != 0) return (error); error = cap_fcntl_check(fdp, fd, needfcntl); if (!fd_modified(fdp, fd, seq)) break; fdrop(fp, td); } if (error != 0) { fdrop(fp, td); return (error); } *fpp = fp; return (0); #endif } /* * Like fget() but loads the underlying vnode, or returns an error if the * descriptor does not represent a vnode. Note that pipes use vnodes but * never have VM objects. The returned vnode will be vref()'d. * * XXX: what about the unused flags ? */ static __inline int _fgetvp(struct thread *td, int fd, int flags, cap_rights_t *needrightsp, struct vnode **vpp) { struct file *fp; int error; *vpp = NULL; error = _fget(td, fd, &fp, flags, needrightsp); if (error != 0) return (error); if (fp->f_vnode == NULL) { error = EINVAL; } else { *vpp = fp->f_vnode; vrefact(*vpp); } fdrop(fp, td); return (error); } int fgetvp(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, 0, rightsp, vpp)); } int fgetvp_rights(struct thread *td, int fd, cap_rights_t *needrightsp, struct filecaps *havecaps, struct vnode **vpp) { struct filecaps caps; struct file *fp; int error; error = fget_cap(td, fd, needrightsp, &fp, &caps); if (error != 0) return (error); if (fp->f_ops == &badfileops) { error = EBADF; goto out; } if (fp->f_vnode == NULL) { error = EINVAL; goto out; } *havecaps = caps; *vpp = fp->f_vnode; vrefact(*vpp); fdrop(fp, td); return (0); out: filecaps_free(&caps); fdrop(fp, td); return (error); } int fgetvp_read(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FREAD, rightsp, vpp)); } int fgetvp_exec(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FEXEC, rightsp, vpp)); } #ifdef notyet int fgetvp_write(struct thread *td, int fd, cap_rights_t *rightsp, struct vnode **vpp) { return (_fgetvp(td, fd, FWRITE, rightsp, vpp)); } #endif /* * Handle the last reference to a file being closed. * * Without the noinline attribute clang keeps inlining the func thorough this * file when fdrop is used. */ int __noinline _fdrop(struct file *fp, struct thread *td) { int error; #ifdef INVARIANTS int count; count = refcount_load(&fp->f_count); if (count != 0) panic("fdrop: fp %p count %d", fp, count); #endif error = fo_close(fp, td); atomic_subtract_int(&openfiles, 1); crfree(fp->f_cred); free(fp->f_advice, M_FADVISE); uma_zfree(file_zone, fp); return (error); } /* * Apply an advisory lock on a file descriptor. * * Just attempt to get a record lock of the requested type on the entire file * (l_whence = SEEK_SET, l_start = 0, l_len = 0). */ #ifndef _SYS_SYSPROTO_H_ struct flock_args { int fd; int how; }; #endif /* ARGSUSED */ int sys_flock(struct thread *td, struct flock_args *uap) { struct file *fp; struct vnode *vp; struct flock lf; int error; error = fget(td, uap->fd, &cap_flock_rights, &fp); if (error != 0) return (error); error = EOPNOTSUPP; if (fp->f_type != DTYPE_VNODE && fp->f_type != DTYPE_FIFO) { goto done; } if (fp->f_ops == &path_fileops) { goto done; } error = 0; vp = fp->f_vnode; lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; if (uap->how & LOCK_UN) { lf.l_type = F_UNLCK; atomic_clear_int(&fp->f_flag, FHASLOCK); error = VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); goto done; } if (uap->how & LOCK_EX) lf.l_type = F_WRLCK; else if (uap->how & LOCK_SH) lf.l_type = F_RDLCK; else { error = EBADF; goto done; } atomic_set_int(&fp->f_flag, FHASLOCK); error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT); done: fdrop(fp, td); return (error); } /* * Duplicate the specified descriptor to a free descriptor. */ int dupfdopen(struct thread *td, struct filedesc *fdp, int dfd, int mode, int openerror, int *indxp) { struct filedescent *newfde, *oldfde; struct file *fp; u_long *ioctls; int error, indx; KASSERT(openerror == ENODEV || openerror == ENXIO, ("unexpected error %d in %s", openerror, __func__)); /* * If the to-be-dup'd fd number is greater than the allowed number * of file descriptors, or the fd to be dup'd has already been * closed, then reject. */ FILEDESC_XLOCK(fdp); if ((fp = fget_noref(fdp, dfd)) == NULL) { FILEDESC_XUNLOCK(fdp); return (EBADF); } error = fdalloc(td, 0, &indx); if (error != 0) { FILEDESC_XUNLOCK(fdp); return (error); } /* * There are two cases of interest here. * * For ENODEV simply dup (dfd) to file descriptor (indx) and return. * * For ENXIO steal away the file structure from (dfd) and store it in * (indx). (dfd) is effectively closed by this operation. */ switch (openerror) { case ENODEV: /* * Check that the mode the file is being opened for is a * subset of the mode of the existing descriptor. */ if (((mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) { fdunused(fdp, indx); FILEDESC_XUNLOCK(fdp); return (EACCES); } if (!fhold(fp)) { fdunused(fdp, indx); FILEDESC_XUNLOCK(fdp); return (EBADF); } newfde = &fdp->fd_ofiles[indx]; oldfde = &fdp->fd_ofiles[dfd]; ioctls = filecaps_copy_prep(&oldfde->fde_caps); #ifdef CAPABILITIES seqc_write_begin(&newfde->fde_seqc); #endif fde_copy(oldfde, newfde); filecaps_copy_finish(&oldfde->fde_caps, &newfde->fde_caps, ioctls); #ifdef CAPABILITIES seqc_write_end(&newfde->fde_seqc); #endif break; case ENXIO: /* * Steal away the file pointer from dfd and stuff it into indx. */ newfde = &fdp->fd_ofiles[indx]; oldfde = &fdp->fd_ofiles[dfd]; #ifdef CAPABILITIES seqc_write_begin(&oldfde->fde_seqc); seqc_write_begin(&newfde->fde_seqc); #endif fde_copy(oldfde, newfde); oldfde->fde_file = NULL; fdunused(fdp, dfd); #ifdef CAPABILITIES seqc_write_end(&newfde->fde_seqc); seqc_write_end(&oldfde->fde_seqc); #endif break; } FILEDESC_XUNLOCK(fdp); *indxp = indx; return (0); } /* * This sysctl determines if we will allow a process to chroot(2) if it * has a directory open: * 0: disallowed for all processes. * 1: allowed for processes that were not already chroot(2)'ed. * 2: allowed for all processes. */ static int chroot_allow_open_directories = 1; SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW, &chroot_allow_open_directories, 0, "Allow a process to chroot(2) if it has a directory open"); /* * Helper function for raised chroot(2) security function: Refuse if * any filedescriptors are open directories. */ static int chroot_refuse_vdir_fds(struct filedesc *fdp) { struct vnode *vp; struct file *fp; int i; FILEDESC_LOCK_ASSERT(fdp); FILEDESC_FOREACH_FP(fdp, i, fp) { if (fp->f_type == DTYPE_VNODE) { vp = fp->f_vnode; if (vp->v_type == VDIR) return (EPERM); } } return (0); } static void pwd_fill(struct pwd *oldpwd, struct pwd *newpwd) { if (newpwd->pwd_cdir == NULL && oldpwd->pwd_cdir != NULL) { vrefact(oldpwd->pwd_cdir); newpwd->pwd_cdir = oldpwd->pwd_cdir; } if (newpwd->pwd_rdir == NULL && oldpwd->pwd_rdir != NULL) { vrefact(oldpwd->pwd_rdir); newpwd->pwd_rdir = oldpwd->pwd_rdir; } if (newpwd->pwd_jdir == NULL && oldpwd->pwd_jdir != NULL) { vrefact(oldpwd->pwd_jdir); newpwd->pwd_jdir = oldpwd->pwd_jdir; } if (newpwd->pwd_adir == NULL && oldpwd->pwd_adir != NULL) { vrefact(oldpwd->pwd_adir); newpwd->pwd_adir = oldpwd->pwd_adir; } } struct pwd * pwd_hold_pwddesc(struct pwddesc *pdp) { struct pwd *pwd; PWDDESC_ASSERT_XLOCKED(pdp); pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (pwd != NULL) refcount_acquire(&pwd->pwd_refcount); return (pwd); } bool pwd_hold_smr(struct pwd *pwd) { MPASS(pwd != NULL); if (__predict_true(refcount_acquire_if_not_zero(&pwd->pwd_refcount))) { return (true); } return (false); } struct pwd * pwd_hold(struct thread *td) { struct pwddesc *pdp; struct pwd *pwd; pdp = td->td_proc->p_pd; vfs_smr_enter(); pwd = vfs_smr_entered_load(&pdp->pd_pwd); if (pwd_hold_smr(pwd)) { vfs_smr_exit(); return (pwd); } vfs_smr_exit(); PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); MPASS(pwd != NULL); PWDDESC_XUNLOCK(pdp); return (pwd); } struct pwd * pwd_hold_proc(struct proc *p) { struct pwddesc *pdp; struct pwd *pwd; PROC_ASSERT_HELD(p); PROC_LOCK(p); pdp = pdhold(p); MPASS(pdp != NULL); PROC_UNLOCK(p); PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); MPASS(pwd != NULL); PWDDESC_XUNLOCK(pdp); pddrop(pdp); return (pwd); } static struct pwd * pwd_alloc(void) { struct pwd *pwd; pwd = uma_zalloc_smr(pwd_zone, M_WAITOK); bzero(pwd, sizeof(*pwd)); refcount_init(&pwd->pwd_refcount, 1); return (pwd); } void pwd_drop(struct pwd *pwd) { if (!refcount_release(&pwd->pwd_refcount)) return; if (pwd->pwd_cdir != NULL) vrele(pwd->pwd_cdir); if (pwd->pwd_rdir != NULL) vrele(pwd->pwd_rdir); if (pwd->pwd_jdir != NULL) vrele(pwd->pwd_jdir); if (pwd->pwd_adir != NULL) vrele(pwd->pwd_adir); uma_zfree_smr(pwd_zone, pwd); } /* * The caller is responsible for invoking priv_check() and * mac_vnode_check_chroot() to authorize this operation. */ int pwd_chroot(struct thread *td, struct vnode *vp) { struct pwddesc *pdp; struct filedesc *fdp; struct pwd *newpwd, *oldpwd; int error; fdp = td->td_proc->p_fd; pdp = td->td_proc->p_pd; newpwd = pwd_alloc(); FILEDESC_SLOCK(fdp); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (chroot_allow_open_directories == 0 || (chroot_allow_open_directories == 1 && oldpwd->pwd_rdir != rootvnode)) { error = chroot_refuse_vdir_fds(fdp); FILEDESC_SUNLOCK(fdp); if (error != 0) { PWDDESC_XUNLOCK(pdp); pwd_drop(newpwd); return (error); } } else { FILEDESC_SUNLOCK(fdp); } vrefact(vp); newpwd->pwd_rdir = vp; vrefact(vp); newpwd->pwd_adir = vp; if (oldpwd->pwd_jdir == NULL) { vrefact(vp); newpwd->pwd_jdir = vp; } pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); return (0); } void pwd_chdir(struct thread *td, struct vnode *vp) { struct pwddesc *pdp; struct pwd *newpwd, *oldpwd; VNPASS(vp->v_usecount > 0, vp); newpwd = pwd_alloc(); pdp = td->td_proc->p_pd; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); newpwd->pwd_cdir = vp; pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } /* * Process is transitioning to/from a non-native ABI. */ void pwd_altroot(struct thread *td, struct vnode *altroot_vp) { struct pwddesc *pdp; struct pwd *newpwd, *oldpwd; newpwd = pwd_alloc(); pdp = td->td_proc->p_pd; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (altroot_vp != NULL) { /* * Native process to a non-native ABI. */ vrefact(altroot_vp); newpwd->pwd_adir = altroot_vp; } else { /* * Non-native process to the native ABI. */ vrefact(oldpwd->pwd_rdir); newpwd->pwd_adir = oldpwd->pwd_rdir; } pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } /* * jail_attach(2) changes both root and working directories. */ int pwd_chroot_chdir(struct thread *td, struct vnode *vp) { struct pwddesc *pdp; struct filedesc *fdp; struct pwd *newpwd, *oldpwd; int error; fdp = td->td_proc->p_fd; pdp = td->td_proc->p_pd; newpwd = pwd_alloc(); FILEDESC_SLOCK(fdp); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); error = chroot_refuse_vdir_fds(fdp); FILEDESC_SUNLOCK(fdp); if (error != 0) { PWDDESC_XUNLOCK(pdp); pwd_drop(newpwd); return (error); } vrefact(vp); newpwd->pwd_rdir = vp; vrefact(vp); newpwd->pwd_cdir = vp; if (oldpwd->pwd_jdir == NULL) { vrefact(vp); newpwd->pwd_jdir = vp; } vrefact(vp); newpwd->pwd_adir = vp; pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); return (0); } void pwd_ensure_dirs(void) { struct pwddesc *pdp; struct pwd *oldpwd, *newpwd; pdp = curproc->p_pd; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (oldpwd->pwd_cdir != NULL && oldpwd->pwd_rdir != NULL && oldpwd->pwd_adir != NULL) { PWDDESC_XUNLOCK(pdp); return; } PWDDESC_XUNLOCK(pdp); newpwd = pwd_alloc(); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); pwd_fill(oldpwd, newpwd); if (newpwd->pwd_cdir == NULL) { vrefact(rootvnode); newpwd->pwd_cdir = rootvnode; } if (newpwd->pwd_rdir == NULL) { vrefact(rootvnode); newpwd->pwd_rdir = rootvnode; } if (newpwd->pwd_adir == NULL) { vrefact(rootvnode); newpwd->pwd_adir = rootvnode; } pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } void pwd_set_rootvnode(void) { struct pwddesc *pdp; struct pwd *oldpwd, *newpwd; pdp = curproc->p_pd; newpwd = pwd_alloc(); PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); vrefact(rootvnode); newpwd->pwd_cdir = rootvnode; vrefact(rootvnode); newpwd->pwd_rdir = rootvnode; vrefact(rootvnode); newpwd->pwd_adir = rootvnode; pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); } /* * Scan all active processes and prisons to see if any of them have a current * or root directory of `olddp'. If so, replace them with the new mount point. */ void mountcheckdirs(struct vnode *olddp, struct vnode *newdp) { struct pwddesc *pdp; struct pwd *newpwd, *oldpwd; struct prison *pr; struct proc *p; int nrele; if (vrefcnt(olddp) == 1) return; nrele = 0; newpwd = pwd_alloc(); sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); pdp = pdhold(p); PROC_UNLOCK(p); if (pdp == NULL) continue; PWDDESC_XLOCK(pdp); oldpwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); if (oldpwd == NULL || (oldpwd->pwd_cdir != olddp && oldpwd->pwd_rdir != olddp && oldpwd->pwd_jdir != olddp && oldpwd->pwd_adir != olddp)) { PWDDESC_XUNLOCK(pdp); pddrop(pdp); continue; } if (oldpwd->pwd_cdir == olddp) { vrefact(newdp); newpwd->pwd_cdir = newdp; } if (oldpwd->pwd_rdir == olddp) { vrefact(newdp); newpwd->pwd_rdir = newdp; } if (oldpwd->pwd_jdir == olddp) { vrefact(newdp); newpwd->pwd_jdir = newdp; } if (oldpwd->pwd_adir == olddp) { vrefact(newdp); newpwd->pwd_adir = newdp; } pwd_fill(oldpwd, newpwd); pwd_set(pdp, newpwd); PWDDESC_XUNLOCK(pdp); pwd_drop(oldpwd); pddrop(pdp); newpwd = pwd_alloc(); } sx_sunlock(&allproc_lock); pwd_drop(newpwd); if (rootvnode == olddp) { vrefact(newdp); rootvnode = newdp; nrele++; } mtx_lock(&prison0.pr_mtx); if (prison0.pr_root == olddp) { vrefact(newdp); prison0.pr_root = newdp; nrele++; } mtx_unlock(&prison0.pr_mtx); sx_slock(&allprison_lock); TAILQ_FOREACH(pr, &allprison, pr_list) { mtx_lock(&pr->pr_mtx); if (pr->pr_root == olddp) { vrefact(newdp); pr->pr_root = newdp; nrele++; } mtx_unlock(&pr->pr_mtx); } sx_sunlock(&allprison_lock); while (nrele--) vrele(olddp); } int descrip_check_write_mp(struct filedesc *fdp, struct mount *mp) { struct file *fp; struct vnode *vp; int error, i; error = 0; FILEDESC_SLOCK(fdp); FILEDESC_FOREACH_FP(fdp, i, fp) { if (fp->f_type != DTYPE_VNODE || (atomic_load_int(&fp->f_flag) & FWRITE) == 0) continue; vp = fp->f_vnode; if (vp->v_mount == mp) { error = EDEADLK; break; } } FILEDESC_SUNLOCK(fdp); return (error); } struct filedesc_to_leader * filedesc_to_leader_alloc(struct filedesc_to_leader *old, struct filedesc *fdp, struct proc *leader) { struct filedesc_to_leader *fdtol; fdtol = malloc(sizeof(struct filedesc_to_leader), M_FILEDESC_TO_LEADER, M_WAITOK); fdtol->fdl_refcount = 1; fdtol->fdl_holdcount = 0; fdtol->fdl_wakeup = 0; fdtol->fdl_leader = leader; if (old != NULL) { FILEDESC_XLOCK(fdp); fdtol->fdl_next = old->fdl_next; fdtol->fdl_prev = old; old->fdl_next = fdtol; fdtol->fdl_next->fdl_prev = fdtol; FILEDESC_XUNLOCK(fdp); } else { fdtol->fdl_next = fdtol; fdtol->fdl_prev = fdtol; } return (fdtol); } struct filedesc_to_leader * filedesc_to_leader_share(struct filedesc_to_leader *fdtol, struct filedesc *fdp) { FILEDESC_XLOCK(fdp); fdtol->fdl_refcount++; FILEDESC_XUNLOCK(fdp); return (fdtol); } static int sysctl_kern_proc_nfds(SYSCTL_HANDLER_ARGS) { NDSLOTTYPE *map; struct filedesc *fdp; u_int namelen; int count, off, minoff; namelen = arg2; if (namelen != 1) return (EINVAL); if (*(int *)arg1 != 0) return (EINVAL); fdp = curproc->p_fd; count = 0; FILEDESC_SLOCK(fdp); map = fdp->fd_map; off = NDSLOT(fdp->fd_nfiles - 1); for (minoff = NDSLOT(0); off >= minoff; --off) count += bitcountl(map[off]); FILEDESC_SUNLOCK(fdp); return (SYSCTL_OUT(req, &count, sizeof(count))); } static SYSCTL_NODE(_kern_proc, KERN_PROC_NFDS, nfds, CTLFLAG_RD|CTLFLAG_CAPRD|CTLFLAG_MPSAFE, sysctl_kern_proc_nfds, "Number of open file descriptors"); /* * Get file structures globally. */ static int sysctl_kern_file(SYSCTL_HANDLER_ARGS) { struct xfile xf; struct filedesc *fdp; struct file *fp; struct proc *p; int error, n; error = sysctl_wire_old_buffer(req, 0); if (error != 0) return (error); if (req->oldptr == NULL) { n = 0; sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; /* overestimates sparse tables. */ n += fdp->fd_nfiles; fddrop(fdp); } sx_sunlock(&allproc_lock); return (SYSCTL_OUT(req, 0, n * sizeof(xf))); } error = 0; bzero(&xf, sizeof(xf)); xf.xf_size = sizeof(xf); sx_slock(&allproc_lock); FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state == PRS_NEW) { PROC_UNLOCK(p); continue; } if (p_cansee(req->td, p) != 0) { PROC_UNLOCK(p); continue; } xf.xf_pid = p->p_pid; xf.xf_uid = p->p_ucred->cr_uid; fdp = fdhold(p); PROC_UNLOCK(p); if (fdp == NULL) continue; FILEDESC_SLOCK(fdp); if (refcount_load(&fdp->fd_refcnt) == 0) goto nextproc; FILEDESC_FOREACH_FP(fdp, n, fp) { xf.xf_fd = n; xf.xf_file = (uintptr_t)fp; xf.xf_data = (uintptr_t)fp->f_data; xf.xf_vnode = (uintptr_t)fp->f_vnode; xf.xf_type = (uintptr_t)fp->f_type; xf.xf_count = refcount_load(&fp->f_count); xf.xf_msgcount = 0; xf.xf_offset = foffset_get(fp); xf.xf_flag = fp->f_flag; error = SYSCTL_OUT(req, &xf, sizeof(xf)); /* * There is no need to re-check the fdtable refcount * here since the filedesc lock is not dropped in the * loop body. */ if (error != 0) break; } nextproc: FILEDESC_SUNLOCK(fdp); fddrop(fdp); if (error) break; } sx_sunlock(&allproc_lock); return (error); } SYSCTL_PROC(_kern, KERN_FILE, file, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE, 0, 0, sysctl_kern_file, "S,xfile", "Entire file table"); #ifdef KINFO_FILE_SIZE CTASSERT(sizeof(struct kinfo_file) == KINFO_FILE_SIZE); #endif static int xlate_fflags(int fflags) { static const struct { int fflag; int kf_fflag; } fflags_table[] = { { FAPPEND, KF_FLAG_APPEND }, { FASYNC, KF_FLAG_ASYNC }, { FFSYNC, KF_FLAG_FSYNC }, { FHASLOCK, KF_FLAG_HASLOCK }, { FNONBLOCK, KF_FLAG_NONBLOCK }, { FREAD, KF_FLAG_READ }, { FWRITE, KF_FLAG_WRITE }, { O_CREAT, KF_FLAG_CREAT }, { O_DIRECT, KF_FLAG_DIRECT }, { O_EXCL, KF_FLAG_EXCL }, { O_EXEC, KF_FLAG_EXEC }, { O_EXLOCK, KF_FLAG_EXLOCK }, { O_NOFOLLOW, KF_FLAG_NOFOLLOW }, { O_SHLOCK, KF_FLAG_SHLOCK }, { O_TRUNC, KF_FLAG_TRUNC } }; unsigned int i; int kflags; kflags = 0; for (i = 0; i < nitems(fflags_table); i++) if (fflags & fflags_table[i].fflag) kflags |= fflags_table[i].kf_fflag; return (kflags); } /* Trim unused data from kf_path by truncating the structure size. */ void pack_kinfo(struct kinfo_file *kif) { kif->kf_structsize = offsetof(struct kinfo_file, kf_path) + strlen(kif->kf_path) + 1; kif->kf_structsize = roundup(kif->kf_structsize, sizeof(uint64_t)); } static void export_file_to_kinfo(struct file *fp, int fd, cap_rights_t *rightsp, struct kinfo_file *kif, struct filedesc *fdp, int flags) { int error; bzero(kif, sizeof(*kif)); /* Set a default type to allow for empty fill_kinfo() methods. */ kif->kf_type = KF_TYPE_UNKNOWN; kif->kf_flags = xlate_fflags(fp->f_flag); if (rightsp != NULL) kif->kf_cap_rights = *rightsp; else cap_rights_init_zero(&kif->kf_cap_rights); kif->kf_fd = fd; kif->kf_ref_count = refcount_load(&fp->f_count); kif->kf_offset = foffset_get(fp); /* * This may drop the filedesc lock, so the 'fp' cannot be * accessed after this call. */ error = fo_fill_kinfo(fp, kif, fdp); if (error == 0) kif->kf_status |= KF_ATTR_VALID; if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) pack_kinfo(kif); else kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); } static void export_vnode_to_kinfo(struct vnode *vp, int fd, int fflags, struct kinfo_file *kif, int flags) { int error; bzero(kif, sizeof(*kif)); kif->kf_type = KF_TYPE_VNODE; error = vn_fill_kinfo_vnode(vp, kif); if (error == 0) kif->kf_status |= KF_ATTR_VALID; kif->kf_flags = xlate_fflags(fflags); cap_rights_init_zero(&kif->kf_cap_rights); kif->kf_fd = fd; kif->kf_ref_count = -1; kif->kf_offset = -1; if ((flags & KERN_FILEDESC_PACK_KINFO) != 0) pack_kinfo(kif); else kif->kf_structsize = roundup2(sizeof(*kif), sizeof(uint64_t)); vrele(vp); } struct export_fd_buf { struct filedesc *fdp; struct pwddesc *pdp; struct sbuf *sb; ssize_t remainder; struct kinfo_file kif; int flags; }; static int export_kinfo_to_sb(struct export_fd_buf *efbuf) { struct kinfo_file *kif; kif = &efbuf->kif; if (efbuf->remainder != -1) { if (efbuf->remainder < kif->kf_structsize) return (ENOMEM); efbuf->remainder -= kif->kf_structsize; } if (sbuf_bcat(efbuf->sb, kif, kif->kf_structsize) != 0) return (sbuf_error(efbuf->sb)); return (0); } static int export_file_to_sb(struct file *fp, int fd, cap_rights_t *rightsp, struct export_fd_buf *efbuf) { int error; if (efbuf->remainder == 0) return (ENOMEM); export_file_to_kinfo(fp, fd, rightsp, &efbuf->kif, efbuf->fdp, efbuf->flags); FILEDESC_SUNLOCK(efbuf->fdp); error = export_kinfo_to_sb(efbuf); FILEDESC_SLOCK(efbuf->fdp); return (error); } static int export_vnode_to_sb(struct vnode *vp, int fd, int fflags, struct export_fd_buf *efbuf) { int error; if (efbuf->remainder == 0) return (ENOMEM); if (efbuf->pdp != NULL) PWDDESC_XUNLOCK(efbuf->pdp); export_vnode_to_kinfo(vp, fd, fflags, &efbuf->kif, efbuf->flags); error = export_kinfo_to_sb(efbuf); if (efbuf->pdp != NULL) PWDDESC_XLOCK(efbuf->pdp); return (error); } /* * Store a process file descriptor information to sbuf. * * Takes a locked proc as argument, and returns with the proc unlocked. */ int kern_proc_filedesc_out(struct proc *p, struct sbuf *sb, ssize_t maxlen, int flags) { struct file *fp; struct filedesc *fdp; struct pwddesc *pdp; struct export_fd_buf *efbuf; struct vnode *cttyvp, *textvp, *tracevp; struct pwd *pwd; int error, i; cap_rights_t rights; PROC_LOCK_ASSERT(p, MA_OWNED); /* ktrace vnode */ tracevp = ktr_get_tracevp(p, true); /* text vnode */ textvp = p->p_textvp; if (textvp != NULL) vrefact(textvp); /* Controlling tty. */ cttyvp = NULL; if (p->p_pgrp != NULL && p->p_pgrp->pg_session != NULL) { cttyvp = p->p_pgrp->pg_session->s_ttyvp; if (cttyvp != NULL) vrefact(cttyvp); } fdp = fdhold(p); pdp = pdhold(p); PROC_UNLOCK(p); efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); efbuf->fdp = NULL; efbuf->pdp = NULL; efbuf->sb = sb; efbuf->remainder = maxlen; efbuf->flags = flags; error = 0; if (tracevp != NULL) error = export_vnode_to_sb(tracevp, KF_FD_TYPE_TRACE, FREAD | FWRITE, efbuf); if (error == 0 && textvp != NULL) error = export_vnode_to_sb(textvp, KF_FD_TYPE_TEXT, FREAD, efbuf); if (error == 0 && cttyvp != NULL) error = export_vnode_to_sb(cttyvp, KF_FD_TYPE_CTTY, FREAD | FWRITE, efbuf); if (error != 0 || pdp == NULL || fdp == NULL) goto fail; efbuf->fdp = fdp; efbuf->pdp = pdp; PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); if (pwd != NULL) { /* working directory */ if (pwd->pwd_cdir != NULL) { vrefact(pwd->pwd_cdir); error = export_vnode_to_sb(pwd->pwd_cdir, KF_FD_TYPE_CWD, FREAD, efbuf); } /* root directory */ if (error == 0 && pwd->pwd_rdir != NULL) { vrefact(pwd->pwd_rdir); error = export_vnode_to_sb(pwd->pwd_rdir, KF_FD_TYPE_ROOT, FREAD, efbuf); } /* jail directory */ if (error == 0 && pwd->pwd_jdir != NULL) { vrefact(pwd->pwd_jdir); error = export_vnode_to_sb(pwd->pwd_jdir, KF_FD_TYPE_JAIL, FREAD, efbuf); } } PWDDESC_XUNLOCK(pdp); if (error != 0) goto fail; if (pwd != NULL) pwd_drop(pwd); FILEDESC_SLOCK(fdp); if (refcount_load(&fdp->fd_refcnt) == 0) goto skip; FILEDESC_FOREACH_FP(fdp, i, fp) { #ifdef CAPABILITIES rights = *cap_rights(fdp, i); #else /* !CAPABILITIES */ rights = cap_no_rights; #endif /* * Create sysctl entry. It is OK to drop the filedesc * lock inside of export_file_to_sb() as we will * re-validate and re-evaluate its properties when the * loop continues. */ error = export_file_to_sb(fp, i, &rights, efbuf); if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) break; } skip: FILEDESC_SUNLOCK(fdp); fail: if (fdp != NULL) fddrop(fdp); if (pdp != NULL) pddrop(pdp); free(efbuf, M_TEMP); return (error); } #define FILEDESC_SBUF_SIZE (sizeof(struct kinfo_file) * 5) /* * Get per-process file descriptors for use by procstat(1), et al. */ static int sysctl_kern_proc_filedesc(SYSCTL_HANDLER_ARGS) { struct sbuf sb; struct proc *p; ssize_t maxlen; u_int namelen; int error, error2, *name; namelen = arg2; if (namelen != 1) return (EINVAL); name = (int *)arg1; sbuf_new_for_sysctl(&sb, NULL, FILEDESC_SBUF_SIZE, req); sbuf_clear_flags(&sb, SBUF_INCLUDENUL); error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) { sbuf_delete(&sb); return (error); } maxlen = req->oldptr != NULL ? req->oldlen : -1; error = kern_proc_filedesc_out(p, &sb, maxlen, KERN_FILEDESC_PACK_KINFO); error2 = sbuf_finish(&sb); sbuf_delete(&sb); return (error != 0 ? error : error2); } #ifdef COMPAT_FREEBSD7 #ifdef KINFO_OFILE_SIZE CTASSERT(sizeof(struct kinfo_ofile) == KINFO_OFILE_SIZE); #endif static void kinfo_to_okinfo(struct kinfo_file *kif, struct kinfo_ofile *okif) { okif->kf_structsize = sizeof(*okif); okif->kf_type = kif->kf_type; okif->kf_fd = kif->kf_fd; okif->kf_ref_count = kif->kf_ref_count; okif->kf_flags = kif->kf_flags & (KF_FLAG_READ | KF_FLAG_WRITE | KF_FLAG_APPEND | KF_FLAG_ASYNC | KF_FLAG_FSYNC | KF_FLAG_NONBLOCK | KF_FLAG_DIRECT | KF_FLAG_HASLOCK); okif->kf_offset = kif->kf_offset; if (kif->kf_type == KF_TYPE_VNODE) okif->kf_vnode_type = kif->kf_un.kf_file.kf_file_type; else okif->kf_vnode_type = KF_VTYPE_VNON; strlcpy(okif->kf_path, kif->kf_path, sizeof(okif->kf_path)); if (kif->kf_type == KF_TYPE_SOCKET) { okif->kf_sock_domain = kif->kf_un.kf_sock.kf_sock_domain0; okif->kf_sock_type = kif->kf_un.kf_sock.kf_sock_type0; okif->kf_sock_protocol = kif->kf_un.kf_sock.kf_sock_protocol0; okif->kf_sa_local = kif->kf_un.kf_sock.kf_sa_local; okif->kf_sa_peer = kif->kf_un.kf_sock.kf_sa_peer; } else { okif->kf_sa_local.ss_family = AF_UNSPEC; okif->kf_sa_peer.ss_family = AF_UNSPEC; } } static int export_vnode_for_osysctl(struct vnode *vp, int type, struct kinfo_file *kif, struct kinfo_ofile *okif, struct pwddesc *pdp, struct sysctl_req *req) { int error; vrefact(vp); PWDDESC_XUNLOCK(pdp); export_vnode_to_kinfo(vp, type, 0, kif, KERN_FILEDESC_PACK_KINFO); kinfo_to_okinfo(kif, okif); error = SYSCTL_OUT(req, okif, sizeof(*okif)); PWDDESC_XLOCK(pdp); return (error); } /* * Get per-process file descriptors for use by procstat(1), et al. */ static int sysctl_kern_proc_ofiledesc(SYSCTL_HANDLER_ARGS) { struct kinfo_ofile *okif; struct kinfo_file *kif; struct filedesc *fdp; struct pwddesc *pdp; struct pwd *pwd; u_int namelen; int error, i, *name; struct file *fp; struct proc *p; namelen = arg2; if (namelen != 1) return (EINVAL); name = (int *)arg1; error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) return (error); fdp = fdhold(p); if (fdp != NULL) pdp = pdhold(p); PROC_UNLOCK(p); if (fdp == NULL || pdp == NULL) { if (fdp != NULL) fddrop(fdp); return (ENOENT); } kif = malloc(sizeof(*kif), M_TEMP, M_WAITOK); okif = malloc(sizeof(*okif), M_TEMP, M_WAITOK); PWDDESC_XLOCK(pdp); pwd = pwd_hold_pwddesc(pdp); if (pwd != NULL) { if (pwd->pwd_cdir != NULL) export_vnode_for_osysctl(pwd->pwd_cdir, KF_FD_TYPE_CWD, kif, okif, pdp, req); if (pwd->pwd_rdir != NULL) export_vnode_for_osysctl(pwd->pwd_rdir, KF_FD_TYPE_ROOT, kif, okif, pdp, req); if (pwd->pwd_jdir != NULL) export_vnode_for_osysctl(pwd->pwd_jdir, KF_FD_TYPE_JAIL, kif, okif, pdp, req); } PWDDESC_XUNLOCK(pdp); if (pwd != NULL) pwd_drop(pwd); FILEDESC_SLOCK(fdp); if (refcount_load(&fdp->fd_refcnt) == 0) goto skip; FILEDESC_FOREACH_FP(fdp, i, fp) { export_file_to_kinfo(fp, i, NULL, kif, fdp, KERN_FILEDESC_PACK_KINFO); FILEDESC_SUNLOCK(fdp); kinfo_to_okinfo(kif, okif); error = SYSCTL_OUT(req, okif, sizeof(*okif)); FILEDESC_SLOCK(fdp); if (error != 0 || refcount_load(&fdp->fd_refcnt) == 0) break; } skip: FILEDESC_SUNLOCK(fdp); fddrop(fdp); pddrop(pdp); free(kif, M_TEMP); free(okif, M_TEMP); return (0); } static SYSCTL_NODE(_kern_proc, KERN_PROC_OFILEDESC, ofiledesc, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_ofiledesc, "Process ofiledesc entries"); #endif /* COMPAT_FREEBSD7 */ int vntype_to_kinfo(int vtype) { struct { int vtype; int kf_vtype; } vtypes_table[] = { { VBAD, KF_VTYPE_VBAD }, { VBLK, KF_VTYPE_VBLK }, { VCHR, KF_VTYPE_VCHR }, { VDIR, KF_VTYPE_VDIR }, { VFIFO, KF_VTYPE_VFIFO }, { VLNK, KF_VTYPE_VLNK }, { VNON, KF_VTYPE_VNON }, { VREG, KF_VTYPE_VREG }, { VSOCK, KF_VTYPE_VSOCK } }; unsigned int i; /* * Perform vtype translation. */ for (i = 0; i < nitems(vtypes_table); i++) if (vtypes_table[i].vtype == vtype) return (vtypes_table[i].kf_vtype); return (KF_VTYPE_UNKNOWN); } static SYSCTL_NODE(_kern_proc, KERN_PROC_FILEDESC, filedesc, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_filedesc, "Process filedesc entries"); /* * Store a process current working directory information to sbuf. * * Takes a locked proc as argument, and returns with the proc unlocked. */ int kern_proc_cwd_out(struct proc *p, struct sbuf *sb, ssize_t maxlen) { struct pwddesc *pdp; struct pwd *pwd; struct export_fd_buf *efbuf; struct vnode *cdir; int error; PROC_LOCK_ASSERT(p, MA_OWNED); pdp = pdhold(p); PROC_UNLOCK(p); if (pdp == NULL) return (EINVAL); efbuf = malloc(sizeof(*efbuf), M_TEMP, M_WAITOK); efbuf->fdp = NULL; efbuf->pdp = pdp; efbuf->sb = sb; efbuf->remainder = maxlen; efbuf->flags = 0; PWDDESC_XLOCK(pdp); pwd = PWDDESC_XLOCKED_LOAD_PWD(pdp); cdir = pwd->pwd_cdir; if (cdir == NULL) { error = EINVAL; } else { vrefact(cdir); error = export_vnode_to_sb(cdir, KF_FD_TYPE_CWD, FREAD, efbuf); } PWDDESC_XUNLOCK(pdp); pddrop(pdp); free(efbuf, M_TEMP); return (error); } /* * Get per-process current working directory. */ static int sysctl_kern_proc_cwd(SYSCTL_HANDLER_ARGS) { struct sbuf sb; struct proc *p; ssize_t maxlen; u_int namelen; int error, error2, *name; namelen = arg2; if (namelen != 1) return (EINVAL); name = (int *)arg1; sbuf_new_for_sysctl(&sb, NULL, sizeof(struct kinfo_file), req); sbuf_clear_flags(&sb, SBUF_INCLUDENUL); error = pget((pid_t)name[0], PGET_CANDEBUG | PGET_NOTWEXIT, &p); if (error != 0) { sbuf_delete(&sb); return (error); } maxlen = req->oldptr != NULL ? req->oldlen : -1; error = kern_proc_cwd_out(p, &sb, maxlen); error2 = sbuf_finish(&sb); sbuf_delete(&sb); return (error != 0 ? error : error2); } static SYSCTL_NODE(_kern_proc, KERN_PROC_CWD, cwd, CTLFLAG_RD|CTLFLAG_MPSAFE, sysctl_kern_proc_cwd, "Process current working directory"); #ifdef DDB /* * For the purposes of debugging, generate a human-readable string for the * file type. */ static const char * file_type_to_name(short type) { switch (type) { case 0: return ("zero"); case DTYPE_VNODE: return ("vnode"); case DTYPE_SOCKET: return ("socket"); case DTYPE_PIPE: return ("pipe"); case DTYPE_FIFO: return ("fifo"); case DTYPE_KQUEUE: return ("kqueue"); case DTYPE_CRYPTO: return ("crypto"); case DTYPE_MQUEUE: return ("mqueue"); case DTYPE_SHM: return ("shm"); case DTYPE_SEM: return ("ksem"); case DTYPE_PTS: return ("pts"); case DTYPE_DEV: return ("dev"); case DTYPE_PROCDESC: return ("proc"); case DTYPE_EVENTFD: return ("eventfd"); case DTYPE_LINUXTFD: return ("ltimer"); default: return ("unkn"); } } /* * For the purposes of debugging, identify a process (if any, perhaps one of * many) that references the passed file in its file descriptor array. Return * NULL if none. */ static struct proc * file_to_first_proc(struct file *fp) { struct filedesc *fdp; struct proc *p; int n; FOREACH_PROC_IN_SYSTEM(p) { if (p->p_state == PRS_NEW) continue; fdp = p->p_fd; if (fdp == NULL) continue; for (n = 0; n < fdp->fd_nfiles; n++) { if (fp == fdp->fd_ofiles[n].fde_file) return (p); } } return (NULL); } static void db_print_file(struct file *fp, int header) { #define XPTRWIDTH ((int)howmany(sizeof(void *) * NBBY, 4)) struct proc *p; if (header) db_printf("%*s %6s %*s %8s %4s %5s %6s %*s %5s %s\n", XPTRWIDTH, "File", "Type", XPTRWIDTH, "Data", "Flag", "GCFl", "Count", "MCount", XPTRWIDTH, "Vnode", "FPID", "FCmd"); p = file_to_first_proc(fp); db_printf("%*p %6s %*p %08x %04x %5d %6d %*p %5d %s\n", XPTRWIDTH, fp, file_type_to_name(fp->f_type), XPTRWIDTH, fp->f_data, fp->f_flag, 0, refcount_load(&fp->f_count), 0, XPTRWIDTH, fp->f_vnode, p != NULL ? p->p_pid : -1, p != NULL ? p->p_comm : "-"); #undef XPTRWIDTH } DB_SHOW_COMMAND(file, db_show_file) { struct file *fp; if (!have_addr) { db_printf("usage: show file \n"); return; } fp = (struct file *)addr; db_print_file(fp, 1); } DB_SHOW_COMMAND_FLAGS(files, db_show_files, DB_CMD_MEMSAFE) { struct filedesc *fdp; struct file *fp; struct proc *p; int header; int n; header = 1; FOREACH_PROC_IN_SYSTEM(p) { if (p->p_state == PRS_NEW) continue; if ((fdp = p->p_fd) == NULL) continue; for (n = 0; n < fdp->fd_nfiles; ++n) { if ((fp = fdp->fd_ofiles[n].fde_file) == NULL) continue; db_print_file(fp, header); header = 0; } } } #endif SYSCTL_INT(_kern, KERN_MAXFILESPERPROC, maxfilesperproc, CTLFLAG_RW, &maxfilesperproc, 0, "Maximum files allowed open per process"); SYSCTL_INT(_kern, KERN_MAXFILES, maxfiles, CTLFLAG_RW, &maxfiles, 0, "Maximum number of files"); SYSCTL_INT(_kern, OID_AUTO, openfiles, CTLFLAG_RD, &openfiles, 0, "System-wide number of open files"); /* ARGSUSED*/ static void filelistinit(void *dummy) { file_zone = uma_zcreate("Files", sizeof(struct file), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); filedesc0_zone = uma_zcreate("filedesc0", sizeof(struct filedesc0), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); pwd_zone = uma_zcreate("PWD", sizeof(struct pwd), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_SMR); /* * XXXMJG this is a temporary hack due to boot ordering issues against * the vnode zone. */ vfs_smr = uma_zone_get_smr(pwd_zone); mtx_init(&sigio_lock, "sigio lock", NULL, MTX_DEF); } SYSINIT(select, SI_SUB_LOCK, SI_ORDER_FIRST, filelistinit, NULL); /*-------------------------------------------------------------------*/ static int badfo_readwrite(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EBADF); } static int badfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } static int badfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (0); } static int badfo_kqfilter(struct file *fp, struct knote *kn) { return (EBADF); } static int badfo_stat(struct file *fp, struct stat *sb, struct ucred *active_cred) { return (EBADF); } static int badfo_close(struct file *fp, struct thread *td) { return (0); } static int badfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { return (EBADF); } static int badfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { return (EBADF); } static int badfo_fill_kinfo(struct file *fp, struct kinfo_file *kif, struct filedesc *fdp) { return (0); } struct fileops badfileops = { .fo_read = badfo_readwrite, .fo_write = badfo_readwrite, .fo_truncate = badfo_truncate, .fo_ioctl = badfo_ioctl, .fo_poll = badfo_poll, .fo_kqfilter = badfo_kqfilter, .fo_stat = badfo_stat, .fo_close = badfo_close, .fo_chmod = badfo_chmod, .fo_chown = badfo_chown, .fo_sendfile = badfo_sendfile, .fo_fill_kinfo = badfo_fill_kinfo, }; static int path_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (POLLNVAL); } static int path_close(struct file *fp, struct thread *td) { MPASS(fp->f_type == DTYPE_VNODE); fp->f_ops = &badfileops; vrele(fp->f_vnode); return (0); } struct fileops path_fileops = { .fo_read = badfo_readwrite, .fo_write = badfo_readwrite, .fo_truncate = badfo_truncate, .fo_ioctl = badfo_ioctl, .fo_poll = path_poll, .fo_kqfilter = vn_kqfilter_opath, .fo_stat = vn_statfile, .fo_close = path_close, .fo_chmod = badfo_chmod, .fo_chown = badfo_chown, .fo_sendfile = badfo_sendfile, .fo_fill_kinfo = vn_fill_kinfo, .fo_flags = DFLAG_PASSABLE, }; int invfo_rdwr(struct file *fp, struct uio *uio, struct ucred *active_cred, int flags, struct thread *td) { return (EOPNOTSUPP); } int invfo_truncate(struct file *fp, off_t length, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_ioctl(struct file *fp, u_long com, void *data, struct ucred *active_cred, struct thread *td) { return (ENOTTY); } int invfo_poll(struct file *fp, int events, struct ucred *active_cred, struct thread *td) { return (poll_no_poll(events)); } int invfo_kqfilter(struct file *fp, struct knote *kn) { return (EINVAL); } int invfo_chmod(struct file *fp, mode_t mode, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_chown(struct file *fp, uid_t uid, gid_t gid, struct ucred *active_cred, struct thread *td) { return (EINVAL); } int invfo_sendfile(struct file *fp, int sockfd, struct uio *hdr_uio, struct uio *trl_uio, off_t offset, size_t nbytes, off_t *sent, int flags, struct thread *td) { return (EINVAL); } /*-------------------------------------------------------------------*/ /* * File Descriptor pseudo-device driver (/dev/fd/). * * Opening minor device N dup()s the file (if any) connected to file * descriptor N belonging to the calling process. Note that this driver * consists of only the ``open()'' routine, because all subsequent * references to this file will be direct to the other driver. * * XXX: we could give this one a cloning event handler if necessary. */ /* ARGSUSED */ static int fdopen(struct cdev *dev, int mode, int type, struct thread *td) { /* * XXX Kludge: set curthread->td_dupfd to contain the value of the * the file descriptor being sought for duplication. The error * return ensures that the vnode for this device will be released * by vn_open. Open will detect this special error and take the * actions in dupfdopen below. Other callers of vn_open or VOP_OPEN * will simply report the error. */ td->td_dupfd = dev2unit(dev); return (ENODEV); } static struct cdevsw fildesc_cdevsw = { .d_version = D_VERSION, .d_open = fdopen, .d_name = "FD", }; static void fildesc_drvinit(void *unused) { struct cdev *dev; dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 0, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/0"); make_dev_alias(dev, "stdin"); dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 1, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/1"); make_dev_alias(dev, "stdout"); dev = make_dev_credf(MAKEDEV_ETERNAL, &fildesc_cdevsw, 2, NULL, UID_ROOT, GID_WHEEL, 0666, "fd/2"); make_dev_alias(dev, "stderr"); } SYSINIT(fildescdev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, fildesc_drvinit, NULL);